Comprehensive DescriptionRead full entry
"Body smooth, naked, but slightly interrupted at base of abdomen. Head transverse, anteriorly rounded, not longer than next segment. Abdomen six-jointed ; first segment nearly concealed under the thorax ; caudal segment subtriangular, a little oblong, broadly rounded at extremity and crenulate, and ornate with spinules and shortish hairs. Caudal appendages not reaching beyond line of abdomen, inner lamella broadly subovate, having crenulations, spinules, and hairs like the caudal segment; the hairs not half as long as the lamella; outer lamella considerably the shorter and half narrower.' This description given by Dana agrees excellently with our specimens, except that in them the inner ramus of the uropods extends slightly beyond the telsonic segment, and the outer ramus is as in Dana's own figure a little over half as broad as the inner. The hind margin of the head is concave. The second and third segments of the peraeon are rather shorter than the rest. The eyes are large, black, wide apart, so that their size is more apparent in a ventral than a dorsal view.
The upper antennae are separated only by the meeting apices of the head's underfolding triangular rostral point and the pentagonal frontal lamina. The first two joints of the peduncle are only faintly separated, and the third joint is subequal in length to the two combined; the first joint of the nine-jointed flagellum is much shorter than the second, the whole reaching a little beyond the peduncle of the second antennae. In these the first three joints are short, the fifth slightly longer than the fourth, the elongate flagellum in the specimen examined consisting of 21 joints.
The mouth-organs are characteristic of the genus. The limbs are of the same general type as in the preceding species, the sixth joint in the first gnathopod is considerably broader than in the two following pairs of legs. Dana observes that ' the fourth joint of the third pair is a little shorter than either the third or fifth pairs, and longer than the tareus.' In our notation this should read that the fifth joint is a little shorter than the fourth or sixth, and longer (but only a little longer) than the seventh.
In the telsonic segment there are four spines on each side of the bifid apical point.
Colour (in spirit) light, with brown speckling of very variable density."