Ausatelson kolle J. L. Barnard 1974

Ausatelson kolle

DESCRIPTION.—Pereonite 4 greatly elongate, bulging dorsally but not protuberant as in A. ule; pereonite 5 with weak lateral ridge locking posterodorsal margin of coxa 4; rostrum of medium size; eyes colorless in alcohol; anterolateral corner of head quadrate; article 1 of antenna 1 with large anterodistal process, articles 2–3 subequal to each other in length, vestigial accessory flagellum present; antenna 2 with article 3 curving medially around front of head, article 5 longer than 4; epistome unproduced, upper lip bilobate slightly asymmetrically; mandible bearing 1-articulate palp with two apical setae basally separate, left lacinia mobilis deeply serrate, right smooth and minutely tuberculate; lower lip with one cone on each main lobe, mandibular processes of medium development; palp of maxilla 1 biarticulate, outer plate with six spines, inner with one long seta; maxilla 2 very small, inner lobe very short; inner plates of maxilliped with two spines, palp article 4 without distinct nail but apex very sharp; coxa 4 with most of ventrolateral area deeply excavate and bounded above by strong elliptic margin, excavate portion of coxa 4 very thin, upper portion thick, internal crescentic chitinous thickening closed externally and not forming strong medial shelf; pereopod 2 smaller than 1 but not “much” smaller as in A. ule; gnathopod 1 with very oblique palm, defined by three stout spines in tandem, dactyl smooth; palm of gnathopod 2 weakly oblique but well defined by obsolescent hump and two especially elongate spines, palm minutely denticulate, dactyl smooth; article 2 of pereopods 3–5 rectolinear, dactyls of all pereopods with apical hook and comb row of pectinations; pleonal epimera 1–3 with softly quadrate posteroventral corners; pleonite 3 with strong dorsal protuberance, 4 not strongly ridged or rugose, pleonites 5 and 6 small and not distinct from one another except by internal sclerites; telson huge, vertically compressed, lateral surface area subequal to lateral surface area of pleonite 4; uropods 1–3 very slender and elongate, uropod 3 uniramous, ramus biarticulate, article 2 as long as article 1; lower part of coxa 4, apex of hump on pleonite 3 and lateral surface of telson bearing pits, each pit with setule, some pits forming craters at heavily chitinized places, pits cordate but craters and pits generally far less abundant than in A. ule; body otherwise sparsely covered with setules in very small pits or pits decreasing in size to width of setule.

Description above comparable to that of A. ule, following notes representing additional points: Right and left mandibles with eight incisorial teeth, left lacinia mobilis with ten teeth; uropod 1 like that of A. ule but apicolateral peduncular margin with only one apical seta; uropod 3 with lateral seta at apex of article 1 and not on peduncle as in A. ule; mandibular palp more elongate than in A. ule; defining spines on gnathopod 2 more elongate; telson more circular from lateral view than in A. ule.

ILLUSTRATIONS.—The following parts conform so rigidly, except where noted in the descriptions, to views illustrated for A. ule that illustrations are not provided for A. kolle: mandibles, maxillae, maxillipeds, pereopods and their dactyls.

HOLOTYPE.—SAM, female, 2.5 mm, unique.

TYPE-LOCALITY.—Shepherd 30, Pearson Islands, South Australia, station B, 15–40 feet, algae, 8 January 1969.

RELATIONSHIP.—The main distinctions of this species from A. ule J. L. Barnard (1972a) are reflected in the key to the species of this genus. Besides those characteristics are the following: less protuberant pereonite 4, more circular telson, longer defining spines of gnathopod 2.

DISTRIBUTION.—Pearson Islands, South Australia, 5–12 m.

Chucullba, new genus

DIAGNOSIS.—Gnathopods 1–2 subchelate, similar to each other in size and shape, highly elongate, palms oblique but shorter than posterior margins of hands; mandible lacking palp (highly vestigial); palp of maxilla 1 biarticulate; antenna 1 bearing or lacking nasiform process on article 1; pereopods 3–5 with rectolinear article 2; pereonite 4 elongate; pleonites 5–6 coalesced basally; telson small, horizontally arranged but fleshy and tall, much smaller than pleonite 4, latter with dorsal enlargement, pleonite 3 dorsally normal; uropod 3 with one article; inner rami of uropods 1–2 shortened.

TYPE-SPECIES.—Chucullba alia, new species (here designated).

RELATIONSHIP.—The italicized portion of the diagnosis distinguishes this genus from Parathaumatelson Gurjanova, based on the unique species Metopella nasica Stephensen (1927) from the Auckland Islands. Two new species are described in Chucullba, one with, the other without, a nasiform projection on antenna 1. The usefulness of this as a generic character is thus diminished in other thaumatelsonin genera, and lessens the distinctions between Thaumatelson Walker and Antatelson J. L. Barnard (1972a). The two genera can now be maintained only on the dissimilarity between gnathopods 1–2 in Thaumatelson and their similarity in Antatelson.

The reduction of uropod 3 is unusual in Stenothoidae, only Raumahara showing a degree of reduction.