Elasmopus bollonsi sp. nov. Figs. 11, 12.

Male.—Third segment of pleon with posterior corner rectangular, not produced, lower portion of posterior margin with small serrations. Fourth segment of pleon smooth and without dorsal carina. First antenna elongate, second antenna with peduncle shorter than that of first, both with numerous long setae and in general resembling the antennae of E. subcarinatus. Mandible with third joint of palp not very slender, hind margin convex, front margin pectinate. First gnathopod shorter than in E. subca inatus and much less setose but with the oblique pectinate row on the inner surface of the propod and with the other setae arranged on the whole as in that species, basal joint stout, merus not ending acutely, carpus as long as the ovate propod. Second gnathopoda unequal, the right one similar to the first but larger, propod nearly twice as long as carpus, setae normal, left gnathopod with basal joint, ischium, and merus all small, carpus small triangular fitting into the outline of the propod which is very large, longer than the rest of the appendage, and abnormally shaped forming with the dactyl an irregular oval, setae few short and scattered, anterior margin sinuous, palm oblique defined by a bluntly rounded lobe and forming a depression on the inner side of the propod, near the finger-hinge is a small flat-topped tooth followed by a larger one of similar shape and then a low convex swelling, dactyl broad with blunt