Terrestrial isopods from the Oued Laou basin, north-eastern Morocco (Crustacea: Oniscidea), with descriptions of two new genera and seven new species

Thirty-four species of terrestrial isopods (Crustacea: Oniscidea) from the Oued Laou basin, in the Rif area of north-eastern Morocco, are recorded. One genus (Paractenoscia) and seven species (Trichoniscus microphthalmus, Paractenoscia cavernicola, Bathytropa rifensis, Soteriscus gibbosus, S. laouensis, Porcellio pseudornatus, and Eluma praticola) are described as new. The genus Soteriscus, unavailable according to article 13.3 of the International Commission on Zoological Nomenclature (ICZN), is here revalidated by choosing S. gaditanus as type species. Six species (Graeconiscus thermophilus, Ctenoscia minima, Platyarthrus parisii, Porcellio humberti, Porcellio flavocinctus and Eluma caelata) have been fully illustrated to facilitate their identifications. Ctenoscia dorsalis Verhoeff is considered to be a junior synonym of C. minima Dollfus. Porcellio ornatus from southern Spain is also figured for comparison with P. pseudornatus sp. nov. The composition and origin of the oniscidean fauna of the Rif region is briefly discussed. http://zoobank.org/urn:lsid:zoobank.org:pub:DCBF3103-1463-4A32-9BC0-A4CFE8B762AE


Introduction
This paper deals with the terrestrial Isopoda collected in the Oued Laou valley in Morocco during a biodiversity survey within the European Union project MEDCORE. The area belongs to the Rif, the coastal mountain chain in the northeastern part of Morocco. In the Oligocene (c. 30 Ma), this chain together with the Betic cordillera was connected to the Iberian peninsula and southern France, and formed a continuous orogenic belt together with the Kabylies, Calabria, Corsica and Sardinia (see the palaeogeographic reconstruction in Rosenbaum et al. 2002). During the Miocene, the Rif-Betic belt moved westward and the formation of the Alboran Sea split the mountain belt into the present Betic cordillera in the south-western Iberian Peninsula and the Rif chain in north-eastern Morocco.
The Oniscidea of this area have been studied in the past by Vandel (1956aVandel ( , 1956bVandel ( , 1958aVandel ( , 1958bVandel ( , 1958c, Schmalfuss (1987), Caruso and Di Maio (1990) and more recently by Achouri et al. (2008aAchouri et al. ( , 2008c, Colombini et al. (2008), Charfi-Cheikhrouha and El Gtari (2008) and Achouri and Charfi-Cheikhrouha (2009). Vandel (1958aVandel ( , 1958b listed 17 species for the whole Rif region while Achouri et al. (2008c) in a paper on the same area of this study (the Oued Laou basin) recognized 20 species, some of which were only identified at genus level. In the present paper 34 species of Oniscidea are recorded, of which seven are described as new. A new genus (Paractenoscia) in the family Philosciidae is described and the genus Soteriscus (Porcellionidae) is revalidated by choosing a type species.

Material and methods
The specimens were collected in 26 stations (St.) (Table 1) during two visits to the Oued Laou valley in May 2004 andSeptember 2005. The area investigated comprehends the Oued Laou basin from the river spring to the mouth in the Mediterranean, including some minor tributaries. All different habitats present in the study area have been investigated, i.e. sandy and rocky littoral shores, cultivated fields, meadows, bushes, woods and some caves. The specimens were stored in 75% ethanol and identifications are based on morphological characters. For each new species the material examined, description, etymology and remarks are given. For each species already recorded from Morocco their bibliographic references, material examined, distribution and remarks (when necessary) are given. Some poorly known species have been illustrated to facilitate their recognition. The taxa are illustrated with figures prepared with the aid of a camera lucida mounted on Wild M5 and M20 microscopes. For some species pictures were taken with a scanning electron microscope.
The material is deposited in the collections of the Museo Zoologico 'La Specola' of the University of Florence, Italy (MZUF) and in the Staatliches Museum für Naturkunde, Stuttgart, Germany (SMNS).

Distribution
Coasts of Black Sea and Mediterranean Sea, Atlantic coasts of the Iberian Peninsula and northern Africa down to Cape Vert, and Macaronesian islands. New record for the Rif region.

Etymology
From the Greek 'mikrós' = small + 'ophthalmós' = eye. The name refers to the reduced eye visible as one to three small dots of dark pigment.

Remarks
The genus Trichoniscus was previously known in Morocco only for the widespread species T. pygmaeus Sars, 1899(Vandel 1959. A second species, Trichoniscus solisensis Vandel, 1959, from a cave near Safi, western Morocco, has been proved to belong to the genus Adoniscus Vandel, 1955c (Olibrinidae) (Taiti and Ferrara 2004). In Algeria four species of Trichoniscus are known: T. gachassini (Giard, 1899), T. fragilis Racovitza, 1908, T. provisorius Racovitza, 1908, and T. peyerimhoffi Vandel, 1955a(Schmalfuss 2003. Another species of Trichoniscus (T. gordoni Vandel, 1955a) is known from several caves in southern Spain and Gibraltar (Vandel 1955a). The new species T. microphthalmus is readily distinguishable from all these species by the male pereopods 1-4 with sternal margin of carpus and merus bearing a fringe of scales, and by the shape of the male pleopod 1 exopod.

Distribution
Graeconiscus thermophilus was previously known from the southern Aegean islands including Crete and western Turkey. New record for the Rif region.

Remarks
Haplophthalmus thermophilus was described by Çağlar (1948) on specimens from a warm spring at Armutlu, near Gemlik (Turkey). Strouhal (1963) redescribed and figured this species from the type locality. Schmalfuss et al. (2004) included the species in the genus Graeconiscus and considered Calconischellus aegeus Schmalfuss, 1972 recorded from Crete and several southern Aegean islands as a junior synonym of G. thermophilus. The specimens from Ghar-Knadel Cave (maximum length ♂ 3 mm, ♀ 3.7 mm) are tentatively identified as Graeconiscus thermophilus since they correspond to the redescription provided by Strouhal (1963, p. 392, Figures 22-26); in the disposition of dorsal ornamentation and the morphology of the male pereopod 7 and pleopod 1. They differ in lacking the eyes and in the shape of the tubercles on pereonite 7 and pleonite 3. In G. thermophilus the pereonite 7 has 3 + 3 tubercles as in the Moroccan specimens but the medial tubercle on each side is much smaller, and the single tubercle on pleonite 3 is transversally elongated while it is rounded in the Ghar-Knadel Cave specimens. The main characters of these specimens are illustrated in Figures 3-5.  Family HALOPHILOSCIIDAE Verhoeff Genus Halophiloscia Verhoeff, 1908 Halophiloscia couchii (Kinahan, 1858) Philoscia couchii; Dollfus, 1896, p. 548 Philoscia Couchii;Paulian de Félice, 1939, p. 192 Halophiloscia couchi;Vandel, 1958a p. 128 Halophiloscia couchii;Taiti and López, 2008, p. 44

Remarks
Ctenoscia minima was originally described by Dollfus (1892) from Grenada, Spain, and later recorded for several localities in Spain, including the Canary and Balearic islands, Portugal (see Schmalfuss 2003 for previous citations), and Morocco (Vandel 1961). This species has been illustrated by Vandel (1946) and Rodríguez and Barrientos (1993). The genus Ctenoscia also includes another species, C. dorsalis (Verhoeff, 1928), originally described from San Remo and Grimaldi (Liguria, Italy), and later recorded from several localities in mainland Spain and the Balearic Islands, Corsica, Italy including Sardinia and Sicily, Malta (see Schmalfuss 2003 for previous citations), and Tunisia (Achouri et al. 2008b). According to the descriptions, C. minima differs from C. dorsalis in having the distal part of the male pleopod 1 endopod bent outwards instead of straight, while all the other characters are identical in the two species. The examination of many specimens of Ctenoscia from the Oued Laou valley showed that C. dorsalis has to be considered as a junior synonym of C. minima. In fact, the distal part of the male pleopod 1 endopod is straight or bent outwards according to the size of the specimens. In the population from St. 14 (Tirinesse), 4 mm long males show the endopod bent outwards as in C. minima ( Figure 8D), while in 4.5 mm long males this appendage is straight as in C. dorsalis ( Figure 8C), showing that this character varies according to the age and size of the specimens. For the same reason also the distal margin of the male pleopod 1 exopod is more or less convex.
Ctenoscia minima is here fully illustrated to facilitate its identification .

Distribution
Portugal, Spain (including Canary and Balearic islands), Corsica, Italy (including Sardinia, Sicily and surrounding islands), Malta, Morocco and Tunisia. New record for the Rif region.
posterior margins of the pereonites. No visible gland pores on lateral margins of pereonites. Cephalon with suprantennal line and without frontal line. Pleon distinctly narrower than pereon; epimera of pleonites 3-5 adpressed, ventrally with small posterior points not visible in dorsal view. Antennule with petaliform aesthetascs. Molar process of mandible dichotomized (i.e. consisting of some plumose setae each arising separately). Outer branch of maxillule with some pectinate teeth; inner branch with short and stout penicils and without posterior point. Inner lobe of maxilla with verruca-like protuberances and a tuft of short segmented sticks. Maxilliped endite without penicil. Pereopods with inner claw of dactylus enlarged. Pleopodal exopod without respiratory structures. Uropods with protopod and exopod grooved on outer margin; insertion of endopod and exopod almost at the same level.

Etymology
From the Greek 'pará' = beside, near + Ctenoscia. The name refers to the similarities with the genus Ctenoscia.

Remarks
Paractenoscia is very similar to the genera Ctenoscia and Anaphiloscia Racovitza, 1907 from the Mediterranean area. It is readily distinguished from both in the maxilla with verruca-like protuberances and a tuft of short sticks on outer lobe; from Ctenoscia also in having the noduli laterales all close to the posterior margin of the pereonites, antennule with petaliform instead of thin aesthetascs, molar process of the mandible dichotomized instead of semidichotomized (i.e. consisting of some plumose setae arising from a common stem, see Ferrara et al. 1995), and maxillular inner branch with short and stout penicils and without posterior point; from Anaphiloscia also in having pointed instead of fan-shaped dorsal scale-setae and dichotomized instead of simple molar penicil. Pectinate maxillular teeth are present also in the genera Benthanops Barnard, 1932from South Africa, Benthana Budde-Lund, 1908, Benthanoides Lemos de Castro, 1958 and Alboscia Schultz, 1995 from South America. Paractenoscia differs from Benthanops in the number and position of the noduli laterales (see Taiti and Ferrara 1982), from Benthana, Benthanoides and Alboscia in the inner branch of the maxillule with short and stout instead of long and thin penicils and in the peculiar shape of the maxilla with the inner lobe covered with verruca-like protuberances and with a tuft of short segmented sticks near the medial margin, features not present in any other genera of Philosciidae.

Description
Maximum length: ♂, 3.5 mm; ♀, 4.8 mm. Body outline as in Figure 9A. Colourless body. Back smooth with some scattered pointed scale-setae ( Figure 9B); noduli laterales with b/c and d/c co-ordinates as in Figure 9C. Cephalon ( Figure 9D, 9E) with suprantennal line slightly bent downwards in the middle; eyes absent. Pereonites 1-3 with convex distal margins and rounded posterior corners; pereonites 4-7 with  progressively more acute corners ( Figure 9F). Telson triangular with slightly convex sides ( Figure 9G). Antennule ( Figure 9H) with third article longer than first and second; third article with two petaliform apical aesthetascs, two petaliform aesthetascs in the middle and one pointed aesthetasc closer to proximal margin. Antenna (Figures 9I,11A) with flagellum slightly longer than fifth article of peduncle; flagellar articles subequal in length; a row of three aesthetascs on second and four aesthetascs on third flagellar article. Mandible with molar penicil consisting of three long and two short setae; left mandible ( Figure 10A) with 2 + 1 free penicils and two lines of scales between the two groups of free penicils; right mandible ( Figure 10B) with 1 + 1 free penicils. Maxillule outer branch with 4 + 6 (4 pectinate) teeth; inner branch with two short stout penicils ( Figure 10C). Maxilla ( Figure 10D) deeply bilobate with setose apex, inner lobe slightly larger than outer one, bearing verruca-like protuberances at the base and with tuft of short segmented sticks near medial margin. Maxilliped ( Figure 10E) endite with a line of setae in the middle and no penicil; first article of palp with two strong setae. Pereopods with a row of scales on distal margins of ischium, merus and carpus.

Description
Maximum length: ♂, 2.8 mm; ♀, 4.0 mm. Colour pale. Body strongly convex with epimera of pereon and pleon enlarged, obliquely directed, clinger type (Schmalfuss 1984). Dorsal surface of cephalon, pereon and pleon with large tubercles and ribs arranged as in Figure 12A. Back covered with triangular scale-setae ( Figure 12B); posterior margins of the body segments with rectangular scale-setae ( Figure 12C); one line of noduli laterales per side arranged on top of the outmost tubercle of the  lobe; no suprantennal line; eye small with five ommatidia. Pereon with quadrangular epimera progressively pointing backwards from first to seventh; posterior margin of the first pereonite slightly sinuous at sides. Pleonites 3-5 with subrectangular epimera continuing the outline of the pereon. Telson slightly wider than long, triangular with straight sides and broadly rounded apex ( Figure 12F). Antennule ( Figure 12G) with second article much shorter than first and third; third article with an apical tuft of four aesthetascs. Antenna ( Figure 12H) with flagellum about as long as fifth article of peduncle; second flagellar article about four times as long as first, bearing a row of four aesthetascs in the middle. Mandibles with molar penicil consisting of four or five hairy setae; left mandible ( Figure 13A) with 2 + 1 free penicils; right mandible ( Figure 13B) with 1 + 1 free penicils. Maxillule ( Figure 13C) outer branch with 4 + 7 (3 cleft) teeth; inner branch with two short stout penicils and a distinct apical point. Maxilla ( Figure 13D) distally bilobate with setose apex; inner lobe much wider than outer one. Maxilliped ( Figure 13E) endite with three triangular stout teeth on distal margin and no penicil; first article of palp with two setae, the medial one much longer than the outer one. Pleopodal exopods with no respiratory structures as in most species of the genus.

Etymology
The name refers to Rif where the specimens have been collected.

Distribution
This littoral species is common along the coasts of Canary Islands, Portugal, Corsica, Italy, Malta and Croatia. It is also recorded from Florida (Taiti and Ferrara 1996), where it is most probably introduced. New record for the Rif region and northern Africa.

Distribution
Known from most lands of the western Mediterranean. New record for the Rif region.

Journal of Natural History 2091
Distribution Canary Islands and Morocco. New record for the Rif region.

Remarks
Platyarthrus parisii was described by Arcangeli (1930) on female specimens from the Canary Islands (Gran Canaria and Tenerife). Vandel (1946) considers this form as a subspecies of P. schoblii Budde-Lund, 1885 and adds a record for Morocco (Mamora Forest, between Rabat and Meknès). Arcangeli (1952) in a discussion on the various subspecies of P. schoblii definitely considers this form as a species (see also Schmalfuss 2003). The specimens from the St. 25 (near Oued Ouara) examined by us show the same large lateral lobes of the cepalon and the same disposition of the dorsal ribs as P. parisii, but differ in the more protruding median frontal lobe. It is difficult to say whether this character can be enough to distinguish a distinct species or it falls within the variability of P. parisii. In order to facilitate a future comparison with the species from the Canary Islands the main characters of the specimens from Oued Ouara are illustrated in Figure 15.

Distribution
Countries encompassed by the Mediterranean Sea, Azores, Madeira, Canary Islands, Cape Verde, Saint Helena and Bermuda.

Journal of Natural History 2093
Previous Rif records Oued Laou region .

Distribution
This species is common in all the lands of the Mediterranean basin where it is native. It has been introduced with human activities in many parts of the world. Previous Rif records Oued Laou .

Distribution
This species occurs in the lands of the Mediterranean, where it is very common along sandy beaches. It is also recorded from Kuwait and Sudan.

Remarks
In Morocco two species of Lucasius have been recorded: L. myrmecophilus Kinahan, 1859, originally described from Algeria (Kinahan 1859); and L. pallidus, originally described from southern France, Sicily, southern Spain and Algeria. In Sicily this species was confused with Mica tardus (Budde-Lund, 1885) and, according to Caruso and Di Maio (1996), it is not present. Achouri et al. (2008c) cite L. myrmecophilus from the Oued Laou basin. The specimens from the same area examined by us definitely fit the description of L. pallidus, but the differences of this species with L. myrmecophilus are still unclear. According to Vandel (1962) and Schmölzer (1965) L. myrmecophilus differs from L. pallidus in having a smooth instead of granulated dorsum, but in the original description by Kinahan (1859) and in the redescription by Budde-Lund (1885, p. 135) it is clearly stated that the dorsum of the body is granulated. Therefore there is a possibility that the two species are synonymous, but a re-examination of the type material of L. myrmecophilus is necessary to confirm this hypothesis.

Distribution
Porcellionides sexfasciatus (Budde-Lund, 1885) is widely distributed in the western Mediterranean region, Atlantic coasts of Europe and northern Africa, including Atlantic islands. It has been also introduced to many other parts of the world. At present P. sexfasciatus includes several subspecies. The specimens from the Rif examined by us belong to P. sexfasciatus lusitanus distributed in Portugal and Morocco (Vandel 1946). New record for the Rif region.

Remarks
These specimens certainly belong to the genus and subgenus Porcellionides, but they do not seem to belong to any of the species of Porcellionides recorded from Morocco or the Iberian Peninsula. This species is morphologically close to P. pruinosus from which it differs in the more granulated dorsum and shape of the male pleopod 2 with exopod having a triangular posterior lobe and endopod tip slightly bent inwards. Since only two specimens were examined, we illustrate the main characters of the species (Figures 16 and 17) but we prefer not to identify the species until a more abundant material can be analysed.

Remarks
Soteriscus was erected by Vandel (1956b) Vandel (1956b), nor by Vandel and Matsakis (1959) when the subgenus was elevated to genus rank, nor in any other subsequent publication dealing with this genus. Thus, according to article 13.3 of ICZN (1999), the name is unavailable (see also Schmidt and Leistikow 2004). In order to revalidate the genus we designate here Metoponorthus (Soteriscus) gaditanus as type species of the genus Soteriscus. For the diagnosis of the genus see Vandel (1960b

Description
Maximum length: ♂, 11 mm; ♀, 15 mm. Body outline as in Figure 18A. Brown colour with numerous yellowish muscle spots; a round pale spot at the base of pereon epimera in the frontal half of the segment; an elongated pale spot in the middle of pereonites and second or third to fifth pleonite; males darker than females. Back smooth with some scattered pointed scale-setae ( Figure 18B); a distinct sulcus marginalis at the sides of pereon epimera with numerous gland pores along its whole length ( Figure 18G); numerous gland pores scattered on the whole dorsal surface of the body; noduli laterales clearly visible, more or less at the same distance from the lateral margin of the pereonites, b/c and d/c co-ordinates as in Figure 18C. Cephalon ( Figure 18D-F) with no suprantennal line, frontal line straight; very small lateral lobes bent downwards and not protruding frontwards; eye with about 25 ommatidia. Pereonites 1-3 with posterior margin regularly convex; pereonite 4 with posterior margin straight; pereonites 5-7 with posterior corners pointing backwards. Pleonites 3-5 with distinct but short posterior points ( Figure 18H). Telson triangular with distinctly concave sides ( Figure 18H). Antennule ( Figure 18I) with first article longer than second and third; third article with a tuft of elongated aesthetascs at apex. Antenna ( Figure 19A) reaching back the posterior margin of pereonite 3; fifth article of peduncle slightly curved, as long as flagellum; first flagellar article about 1.6 as   long as second. Mandibles ( Figure 19B, C) with molar penicil dichotomized and a line of several free penicils. Maxillule outer branch with 4 + 6 teeth (3 slightly cleft); inner branch with a distinct posterior point and two long and thin penicils ( Figure 19D). Maxilla ( Figure 19E) bilobate with setose apex, inner lobe quadrangular, much smaller than outer one; two long setae on the margin between the two lobes. Maxilliped ( Figure 19F) endite with two small triangular setae on distal margin and no penicil; first article of palp with two strong setae. Pleopod 1 and 2 exopods with monospiracular covered lungs. Uropod ( Figure 18H) with a triangular depression on protopodal outer margin; exopod almost twice as long as endopod; endopod proximally inserted.
Male: Carpus of pereopod 1 ( Figure 20A) to 3 with a brush of pointed setae increasing in length distally. Pereopod 7 ( Figure 20B) ischium with straight sternal margin and a longitudinal depression in the middle of the rostral surface; merus with a distinct hump on the posterior half of tergal margin. Pleopod 1 ( Figure 20C) exopod with large medial lobe about twice as long as wide, with largely rounded apex bearing a line of short setae; endopod with distal part with almost parallel sides and a tuft of short setae at apex. Pleopod 2 ( Figure 20D) endopod slightly longer than exopod. Pleopod 3-5 exopods as in Figure 20E-G.

Etymology
From the Latin 'gibbosus' = having a hump. The name refers to the male pereopod 7 merus which shows a distinct hump on the posterior half of tergal margin.

Remarks
At present the genus Soteriscus includes 15 species from Atlantic islands (Madeira Archipelago, Canary Islands and Cape Verde), northern Morocco, northern Algeria and southern Spain (Schmalfuss 2003). Three species have been recorded in northeastern Africa (Vandel 1956b(Vandel , 1958a(Vandel , 1960b: S. gaditanus, S. virescens (Budde-Lund, 1885) and S. fuscovariegatus (Lucas, 1849). Of these species, only S. gaditanus was recorded from the Rif region (Vandel 1956b(Vandel , 1958aAchouri et al. 2008aAchouri et al. , 2008c, but this species has not been collected by us. Re-examination of the material identified as S. gaditanus from the Rif region is necessary to confirm its occurrence. Soteriscus gibbosus differs from all the other species in the genus in having a distinct hump on the male pereopod 7 merus. In having the male pleopod 1 exopod with a large medial lobe, the news species shows affinities with S. gaditanus and S. fuscovariegatus, but in both these two species the medial lobe is distinctly more slender. It also differs from the former in having a broadly rounded instead of triangular apical part of the medial lobe of the male pleopod 1 exopod (see Figure 2B in Vandel 1956b), and in the thicker and shorter uropodal exopods (see Figure 2A in Vandel 1956b); from the latter in having shorter frontal lateral lobes and longer and more slender uropodal exopods (see Figure 3A, B in Vandel 1956b).

Description
Maximum length: ♂, 13 mm; ♀, 16 mm. Body enlarged, outline as in Figure 21A. Colour: male brown-grey with the usual yellowish muscle spots; female light brown with a marbled pattern, two darker spots per side on the anterior part of pereonites; antennae uniformly grey; pereopods pale with numerous dark spots; pleopodal exopods dark. Back smooth with some scattered short triangular scalesetae ( Figure 21B); a distinct sulcus marginalis on lateral margins of pereon epimera with numerous gland pores along its whole length ( Figure 21G); numerous gland pores scattered on the whole dorsal surface of the body; noduli laterales clearly visible, inserted more or less at the same distance from the lateral margin of the pereonites, b/c and d/c co-ordinates as in Figure 21C. Cephalon ( Figure 21D-F) with no suprantennal line, frontal line straight; very small lateral lobes bent downwards and not protruding frontwards; eye with about 26 ommatidia. Pereonites 1-3 with posterior margin regularly convex; pereonite 4 with posterior margin straight; pereonites 5-6 with posterior corners pointing backwards, pereonite 7 with acute posterior corners and slightly sinuous posterior margin at sides. Pleonites 3-5 with well-developed falciform posterior points ( Figure 21H). Telson triangular with distinctly concave sides ( Figure 21H). Antennule ( Figure 21I) with first article longer than second and third; third article with a short triangular point and a tuft of elongated aesthetascs at apex. Antenna ( Figure 21J) reaching back posterior margin of pereonite 3; fifth article of peduncle almost as long as flagellum; first flagellar article about 1.5 longer than second. Buccal pieces as in the preceding species. Pleopodal exopods 1 and 2 with monospiracular covered lungs. Uropod ( Figure 21K) with a triangular depression on protopodal outer margin; exopod about twice as long as endopod; endopod proximally inserted.
Male: Carpus and distal part of merus of pereopod 1 ( Figure 22A), pereopod 2 and, to a lesser extent, pereopod 3 with a brush of pointed setae. Pereopod 7 ( Figure 22B) ischium with slightly convex sternal margin and a longitudinal depression and a setose area on rostral surface; merus elongated, without peculiar structures. Pleopod 1 ( Figure 22C) exopod with long medial lobe almost three times as long as wide, with some short setae along its margin and a broadly rounded apex; endopod with distal part with almost parallel sides and a tuft of short setae at apex. Pleopod 2 ( Figure 22D) endopod distinctly longer than exopod. Pleopod 3-5 exopods as in Figure 22E-G.

Etymology
The species is named after the Oued Laou basin, where the specimens were collected.

Remarks
In having the male pleopod 1 exopod with a long medial lobe S. laouensis is similar to S. gaditanus, S. fuscovariegatus and S. gibbosus sp. nov. It is readily distinguishable from S. gaditanus in having the male pleopod 1 exopod with broadly rounded instead of triangular apical part and shorter uropodal exopods; from S. fuscovariegatus in the less protruding lateral lobes of cephalon (see Figure 3A in Vandel 1956b) and comparatively longer and thinner uropods; and from S. gibbosus in lacking the hump on the male pereopod 7 merus and distinctly thinner medial lobe of the male pleopod 1 exopod.

Description
Maximum length: ♂, 22 mm; ♀, 23 mm. Body outline as in Figure 23A. Colour brown-grey with pale marginal parts of frontal lateral lobes and epimera of pereon and pleon; sometimes with two paramedian yellowish round spots on pereonites 5-7 and pleonites 2-4; antennae uniformly grey, pereopods and pleopod 1-2 exopods pale, pleopod 3-5 exopods dark. Dorsal surface of cephalon, pereon and pleon distinctly granulated with many scattered short triangular scale-setae ( Figure 22B); numerous gland pores in rounded fields disposed near the anterior corner of pereonite 1 and more or less in the middle of pereonites 2-7 close to the lateral margins of the segments ( Figure 22A, E); noduli laterales small, the ones on pereonites 1-4 inserted about twice more distant from the lateral margin than those on pereonites 5-7 ( Figure 23A). Cephalon ( Figure 22C, D) with no suprantennal line; large rounded lateral lobes obliquely bent downwards and distinctly protruding frontwards, median lobe widely rounded, often slightly incised at the apex; eye with about 30 ommatidia. Pereonites 1-3 with hind margin slightly concave at sides, more distinct on pereonite  long with a triangular distal part. Antennule ( Figure 23G) with first article distinctly longer than second and third; third article with a tuft of short aesthetascs near the apex. Antenna ( Figure 23H) reaching back or slightly surpassing the posterior margin of pereonite 3; fifth article of peduncle shorter than flagellum; first flagellar article about twice as long as second. Mandibles ( Figure 24A, B) with molar penicil dichotomized and a line of eight free penicils. Maxillule ( Figure 24C) outer branch with 4 + 6 teeth, all simple; inner branch with a distinct posterior point and two long and thin penicils. Maxilla ( Figure 24D) bilobate with setose apex, inner lobe quadrangular, much smaller than outer one; two long setae on the margin between the two lobes. Maxilliped ( Figure 24E) endite with two small triangular setae on distal margin and no penicil; first article of palp with two strong setae. Pleopodal exopods 1 and 2 with monospiracular covered lungs ( Figure 25C, D). Uropod ( Figure 23A, F) with a triangular depression on protopodal outer margin, not visible in dorsal view.
Male: Uropodal exopods ( Figure 23F) flattened, elongated and much longer than in females (4 times as long as wide in males, less than 3 times in females). Merus and carpus of pereopod 1 ( Figure 25A) to 4 and, to a lesser extent, 5 with a brush of pointed setae. Pereopod 7 ( Figure 25B) ischium distally enlarged with a transversal depression and a setose area on rostral surface; sternal margin slightly convex; carpus with a large rounded lobe on distal half of tergal margin. Pleopod 1 ( Figure 25C) exopod with long medial lobe with parallel sides, oblique and sinuous distal margin with three strong setae at apex, and some short setae along the medial margin; endopod with distal part straight, rounded and setose apex. Pleopod 2 ( Figure 25D) exopod triangular and slightly shorter than endopod. Pleopod 3-5 exopods as in Figure 25E-G.

Etymology
From the stem of the Greek 'Pseudes' = false, erroneous + ornatus. The species name refers to the similarity with Porcellio ornatus Milne-Edwards, from south-eastern Spain.

Remarks
According to Vandel (1958a), four species of the Rif-Betic group of Porcellio occur in the Rif region: P. ornatus Milne-Edwards; P. wagneri Brandt, 1841; P. hoffmannseggii Brandt, 1833; and P. echinatus Lucas, 1849. The specimens here examined do not seem to belong to any of these four species, nor to any other species in this group, even if they are strictly related to P. ornatus and P. wagneri. Specimens of P. ornatus collected from the type locality in south-eastern Spain (many ♂♂ and ♀♀, Cartagena, Murcia, leg. M. Rizzotti Vlach, 4 August 1981, MZUF 9594) have been examined and are here illustrated (Figures 26 and 27) for comparison with our specimens from the Oued Laou basin. Porcellio pseudornatus differs from P. ornatus in the dorsal body surface more granulated, wider dorsal scale-setae, posterior margin of pereonites 1-3 more concave at the sides, thinner antennae, much longer male uropodal exopods and more pronounced rounded lobe on the male pereopod 7 carpus. According to the figures provided by Lucas (1849, plate 6, Figures 6A-C); for P. wagneri originally described from Algeria, the new species differs in having the  male uropodal exopods much wider (4 times as long as wide vs. 7.5 times in P. wagneri). The material of P. ornatus and P. wagneri from the Rif studied by Vandel (1958a) needs to be re-examined to confirm that also these two species are present in the area.

Distribution
Portugal, southern Spain and northern Morocco.

Remarks
These specimens are identified as P. flavocinctus after comparison with the redescription of this species provided by Arcangeli (1936, p. 190, Figures 1-7). The main characters of the specimens from the Oued Laou valley are here illustrated ( Figures  28 and 29) and they fit well those of P. flavocinctus provided by Arcangeli. The record of Budde-Lund (1885) from El Araisch (= Larache) in northern Morocco was considered doubtful by Arcangeli (1936). Our record from the Oued Laou valley together with those by Vandel (1958a) from the Rif confirms that this species is also present in this part of north-western Africa.

Distribution
Southern Spain, southern Portugal and northern Morocco.

Distribution
Europe and northern Africa, introduced to many parts of the world.

Distribution
Northern Morocco.

Distribution
Southern Portugal, southern Spain, northern Morocco, and north-western Algeria.

Journal of Natural History 2119
Distribution Southern Spain and Morocco.

Description
Maximum length: ♂, 5.5 mm; ovigerous ♀, 7 mm. Body very convex, able to roll up into a ball, euspheric type ( Figure 34A). Colour brown with paler epimera of pereonites 2-7. Dorsal surface without ornamentation and with numerous round     pits and tiny pointed scale-setae ( Figure 35A); one line of noduli laterales per side far from the lateral margin of pereonites 1-6, two noduli laterales per side on pereonite 7 ( Figure 34D); no visible gland pores. Cephalon ( Figure 34B, C) with a wide triangular scutellum distinctly separated from and not bent over vertex; no postscutellar line; antennary lobes quadrangular, directed frontwards; eye consisting of a single large ocellus. Pereonite 1 (Figures 34B, 35B) with a flattened lateral margin and a schisma on posterior corners; inner lobe of schisma rounded, more protruding backwards than the outer one; a small triangular lobe on ventral surface; posterior margin slightly sinuous at sides. Pereonite 2 ( Figure 35B) with rounded epimera, a small triangular ventral lobe and straight posterior margin. Pereonite 3 with rounded epimera and straight posterior margin; pereonites 4-7 with quadrangular epimera and straight posterior margins. Pleonites 3-5 with rectangular epimera, slightly divergent. Telson ( Figure 34E) triangular, almost 1.5 as wide as long, with straight sides and broadly rounded apex. Antennule ( Figure 35C) of three articles, second article much shorter than first and third, third article with a tuft of superimposed aesthetascs subapically. Antenna ( Figure 35D) short and stout with flagellum slightly shorter than fifth article of peduncle, second flagellar article almost three times longer than first and bearing two rows of aesthetascs. Mandibles ( Figure 35E, F) with semidichotomized molar penicil and four free penicils; right mandible with one penicil and left mandible with two penicils on the hairy lobe. Maxillule ( Figure 35G) outer lobe with 4 + 6 (5 cleft) teeth; inner lobe with two subequal penicils and a small triangular distal point. Maxilla ( Figure 35H) apically setose, with quadrangular inner lobe, much smaller than rounded outer lobe. Maxilliped ( Figure 35I) with quadrangular endite bearing three short triangular setae on distal margin and a longer subapical seta near the inner corner; basal article of palp with two long setae. Uropod ( Figures 34E, 36A) flattened; exopod about twice as wide as long, with concave distal margin; endopod distinctly more protruding backwards compared with exopod.
Male: Pereopod 1 ( Figure 36B) with a line of pointed setae on sternal margin of carpus and, to a lesser extent, merus. Pereopod 7 ( Figure 34F, G) ischium distally with a ridge on caudal surface, sternal margin slightly concave with numerous long setae; merus with no ridges or lobes, sternal margin slightly convex with some long setae. Pleopod 1 ( Figure 36C) exopod with a short, rounded medial lobe; endopod with distal part pointed and bent outwards. Pleopod 2 ( Figure 36D) exopod triangular and slightly shorter than endopod. Pleopod 3-5 exopods as in Figure 36E-G.

Etymology
From the Latin pratum = meadow + stem of colere = to live. The name refers to the habitat where the specimens have been collected.

Remarks
Up to date the genus Eluma included only two species, the widespread E. caelata and E. tuberculata Cruz, 1991 from Fatima, Portugal. The new species is similar to E. caelata from which it differs in smaller size (maximum length in ovigerous females 7 mm vs 16 mm), the dorsal surface with shorter and less numerous scale-setae (compare Figure 34A-E and Figure 32A-D), shorter uropodal exopod (compare Figures 34E and Figure 32C), male pereopod 7 without a basal triangular lobe on merus and less sharp ridge on the caudal surface of the ischium (compare Figure 34F, G and Figure 32E-G), and pleopod 1 exopod with a shorter and round medial lobe (compare Figure 36C and Figure 33C). Eluma praticola is readily distinguishable from E. tuberculata in the dorsal surface without ornamentation and lateral margin of pereonite 1 not grooved. No comparison is possible with the male characters since E. tubercolata was described on female specimens (Cruz 1991).

Distribution
Atlantic coast of Europe, western and central Mediterranean as far East as Greece.

Distribution
Mediterranean basin, Morocco and Portugal.

Discussion
In the present study 34 species of terrestrial isopods are recorded from the Oued Laou basin and summarized in Figure 37. Two genera (Paractenoscia and Soteriscus) and seven species (   Vandel (1958a) recorded 17 species from the Rif area, many of which have also been encountered in the Oued Laou basin. Six of these species (Lucasius myrmecophilus, Soteriscus gaditanus, Porcellio ornatus, P. wagneri, Armadillidium djebalensis Vandel, 1958b andA. pardoi Vandel, 1956a) are not present in the collection examined by us, but we must point out the taxonomic uncertainties concerning L. myrmecophilus (see remarks under L. pallidus) and the possible misidentification of P. ornatus which probably has to refer to P. pseudornatus sp. nov.
In a more recent publication on the diversity of terrestrial isopods from the same area considered in this study, Achouri et al. (2008c) listed 19 species, six of which identified only at genus level (Porcellio sp. 1, Porcellio sp. 2, Porcellionides sp., About 59% of the species have wide distributions (Groups 1-5), all of Mediterranean origin. Seven of these species (Ligia italica, Tylos europaeus, Halophiloscia couchii, Stenophiloscia glarearum, Stenoniscus carinatus, Porcellio lamellatus and Armadillidium album) are halophilic and widely distributed along the sandy and rocky shores of the Mediterranean Sea and some also on the Atlantic coasts of Africa and Europe.
The number of species with more limited distributions and more significant from a zoogeographical point of view is quite high (Groups 6 and 7, 16 spp., 41%). Most of these species are also distributed in the southern part of the Iberian Peninsula (Group 6) or are endemic to the Rif but showing affinities with Iberian species: Soteriscus gibbosus, S. laouensis which are morphologically close to S. gaditanus; Porcellio pseudornatus and P. riffensis, belonging to the Rif-Betic group of Porcellio; Eluma praticola belonging to an Atlantic genus; and Armadillidium djebalensis and A. pardoi, belonging to the serratum group of Armadillidium. All these examples seem to show a common origin of the fauna of the Rif with that of the Betic cordillera, which were in connection until the middle Miocene (Rosenbaum et al. 2002).