Fig. 50

Mortoniella gracilis is very similar to M. variabilis, n. sp. and M. limona (Flint), as discussed in the diagnoses for those species. All of these species are characterized by elongate sclerotized projections from the ventral surface of the phallicata. The ventral projection is variable in length and shape, even within the respective species, and thus the exact shape is not reliably diagnostic. Mortoniella gracilis can generally be distinguished from the other two species by the much more slender, less projecting, ventral protrusion of the apex of the dorsal phallic spine. There is often a spine-like projection from the posterior margin of this apical expansion; this is more likely to be preapical and slightly downturned, rather than upturned from the ventral margin, which is more typical of M. variabilis. The armature of the endophallic membrane is most similar to M. limona in that it is composed of 2 pairs of distinctly sclerotized spines. In M. variabilis, 1 of the pairs of spines is typically either small and lightly sclerotized (and thus not readily visible), or possibly absent in some specimens.

Adult —Length of forewing: male 2.9-3.4 mm; female 3.0-3.8. Forewing with forks I, II, and III present, hind wing with forks II and III. Spur formula 0:4:4. Overall color medium brown, apices of tarsal segments and basal segments of antennae pale brown. Tibial spurs darker than legs, contrasting in color. Wing bar at anastamosis indistinct, marked with light brown setae, most evident at arculus.

Male genitalia —Ventral process of segment VI laterally compressed, ventrally projecting, large, subtriangular, length slightly greater than width at base, process not retracted anterobasally. Segment IX nearly evenly rounded anterolaterally, length greatest midlaterally, posterolateral margin weakly rounded, narrowing ventrally; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by less than ½ width of segment. Tergum X relatively short, lateral margins subparallel, apicomesal margin with V-shaped (usually) or U-shaped emargination between apicolateral lobes, emargination extending about 1/3 length of segment, apicolateral lobes tapered, acute apically, lobes very short and narrow as viewed laterally; apicomesal lobes visible in lateral view, rounded apically; ventrolateral lobes distinct, projecting. Inferior appendages with short rounded dorsolateral projections and very short acute paired apicoventral projections. Mesal pockets of inferior appendage with apical processes moderately large, posterodorsally curved. Paramere appendage elongate (subequal to dorsal phallic spine), narrow, nearly uniformly in width, apex acute. Dorsal phallic, as viewed laterally, compressed apically, with weakly rounded apicoventral expansion, posterior margin usually with evident acute, slightly down-turned, preapical projection; spine in dorsal view, nearly uniform in width, apex acute. Phallicata with dorsal margin sclerotized, extending into endophallic membrane, basoventrally with pair of very prominent curved, apically rounded sclerotized projections. Endophallic membrane short, with 2 pairs of enlarged sclerotized spines (possibly phallotremal complex); ventromesal spine absent.

Holotype male (pinned)— VENEZUELA: Sucre: Peninsula de Paria, Puerto Viejo, “Río el Pozo,” 10.71788° N, 62.47615° W, el 20 m, 2-3.iv.1995, Holzenthal, Flint, Cressa (UMSP000001425) (UMSP).

Paratypes — VENEZUELA: Barinas: 22 km NW Barinas, 24.ii.1976, CM and OS Flint, Jr – 1 male, 8 females (pinned) (NMNH); Monagas: Guachero Cave N. P., 10.172033° N, 63.555250° W, el 1110 m, 20-21.vii.2010, Holzenthal, Thomson, Cressa– 2 males, 1 female (pinned) (UMSP); Sucre: Quebrada Zapateral, 1.5 km SE Las Piedras de Cocollar, 10.16255° N, 63.79312° W, el 810 m, 9.iv.1995, Holzenthal and Flint– 2 males, 4 females (pinned); 3 males, 2 females (alcohol) (NMNH); Peninsula de Paria, Santa Isabel, Río Santa Isabel, 10.67157° N, 62. 64923° W, el 20 m, 4.iv.1995, Holzenthal, Flint, Cressa– 1 male, 12 females (pinned); 3 males, 45 females (alcohol) (UMSP); same data as Holotype– 9 males, 12 females (pinned), 23 males, 45 females (alcohol) (UMSP); Peninsula de Paria, Puerto Viejo, Río Puerto Viejo, 10.71895° N, 68.47905.° W, el 15 m, 2.iv.1995, Holzenthal, Flint, Cressa– 7 males, 11 females (alcohol) (MIZA); Río Cocollar, 1.5 km SE Las Piedras de Cocollar, 10.16028° N, 63.79342° W, el 810 m, 7-8.iv.1995, Holzenthal and Flint– 9 males, 9 females (pinned), 66 males, 58 females (alcohol) (UMSP).

Etymology —This species is named M. gracilis, from the Latin word for slender, and referring to the relatively narrow apex of the dorsal phallic spine, which character helps to distinguish it from its most closely related species.