(Fig. 7 K–N)
Material examined. Stn. 8, 27.i.2012, 9– 15 m, M076: fertile (female) colony on Thyroscyphus marginatus (Allman, 1877). Additional material for comparison: Tristan da Cunha group, Inaccessible Island, Stn 7. I10, 28.xi. 2007, HRG-0341: several sterile stems.
Remarks. Compared to the material from Inaccessible Island studied earlier by myself (Galea 2010 b), the present specimens have smaller hydrothecae, the lateral nematothecae of the anterior pair are shorter (compare Fig. 7 M 1 and M 2), and the ahydrothecate segments bear 3 or 4 nematothecae in two parallel, closely set rows (Fig. 7 K), instead of only one, occasionally two.
The cnidome of the Caribbean material is composed of three types of capsules (Fig. 7 N 1): 1) seed-shaped microbasic heteronemes, ca. 4.2 × 2.6 µm, occurring rarely in the coenosarc; 2) small, banana-shaped microbasic mastigophores, ca. 6.4 × 2.2 µm, abundant in the tentacles, also scattered in the coenosarc; 3) large, ovoid microbasic heteronemes with thick shaft (pseudostenoteles?), (14.1 –16.0)×(5.6–6.4) µm, occurring in the nematophores, also scattered in the coenosarc.
In contrast, the large microbasic heteronemes in material from Inaccessible Island are smaller, slender, and more tubular [(11.2–12.5)×(3.8 –4.0) µm], and their shaft is less conspicuous (Fig. 7 N 2).
Given: 1) the extreme variability in size of the stems and the number of hydrothecae they carry [from 1.4 cm high and 9 hydrothecae in Ritchie's (1909) material from Gough Island, to up to 6 cm high and 40 hydrothecae in the Indian specimens studied by Leloup (1932)]; 2) the shape (walls parallel or divergent) and size of the hydrothecae; 3) the shape of the upper chamber of the first pair of lateral nematothecae (see variation in Schuchert 1997); 4) the varied number of nematothecae (from 1 to 4) carried by the ahydrothecate segments (Millard 1977); 5) the lack of data on the cnidome composition in nearly all the previous records from around the world; 6) the lack of knowledge on the nature of the gonophores,
I raise the question of the specific limitation in A. quadriaurita, and I refrain from including with certainty the present material in the synonymy of this species, pending a broader study based on specimens from various localities around the world.
Geographical distribution. Likely unsettled at present, though a summary of the world records is given by Schuchert (1997); to this, it should be added a recent record from Brazil (Grohmann et al. 2003). In the Caribbean, the species was found in Cuba (Stechow 1919 a 8), Belize (Spracklin 1982), and Martinique (present study).
7. See Galea (2010b) for details.
8. Upon the reexamination of the material from Havana, Cuba, assigned by Nutting (1900) to A. gracilis Allman, 1877, Stechow (1919) reached the conclusion that it belonged instead to A. quadriaurita, due the presence of a second pair of smaller lateral nematothecae behind the hydrotheca.
- small, seed-shaped heteronemes ca. 4.0× 2.6 ca. 4.2 × 2.6 ca. 3.5 × 2.4 not found, but likely
present - large heteronemes (gonophore) (9.6 –12.0)×(2.9–3.2) absent absent absent