364 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.39. 



Abdomen three-jointed, the first joint as wide as the posterior end 

 of the genital segment, the other joints diminishing regularly. Anal 

 lamince shorter than the last abdomen joint and less than half its 

 width, each bearing three setse, of which the inner one is twice the 

 length of the outer. There is also a short spine at the base of each 

 lamina on the outer margin. Egg-cases elongate, about two-thirds 

 the entire length and three times as long as wide. 



First antennae very large, each one-fourth longer than the cephalo- 

 thorax, probably six-jointed, but with the joints of the basal portion 

 indistinctly separated. These basal joints are much enlarged and 

 are attached to the front of the carapace some little distance apart, 

 with a fringe of large flattened setse around their anterior margin. 

 They are operated by a set of powerful muscles which extend diago- 

 nally backward and inward nearly to the posterior margin of the 

 cephalothorax and which are plainly visible in dorsal view. On the 

 dorsal surface of the third joint of each antenna are two long tactile 

 hairs which point directly forward. The second antennae are two- 

 jointed, the last joint with the usual roughened surfaces and terminal 

 claws. 



The mouth-parts agree with those of Bomolochus in the main par- 

 ticulars, but differ in details. The labrum is much broader than long 

 and crescentic, projecting at the angles on either side. The mandibles 

 are three- jointed, the basal joint much wider than the others, about 

 one-third the entire length of the appendage, and evenly rounded at 

 the distal end. The second joint is shorter and narrower, and bears 

 at its distal end both a cutting blade and a palp. The former is 

 longer than even the basal joint and quite narrow, with a fringe of 

 short hairs along its posterior border. 



The latter consists of a rounded knob terminated by a short curved 

 claw, and is ventral to the cutting blade. 



The first maxillae are elevated well above the surface of the head, 

 and each is armed with three widely divergent seise. The second 

 maxillae have a long and narrow basal joint, running back to the 

 basal joint of the mandibles, and a slender cutting blade turned 

 diagonally forward, a little more than half as long as the basal joint 

 and entirely smooth. 



Tli8 maxillipeds are comparatively small, the basal joint is triangu- 

 lar and armed with powerful muscles, while the terminal claw is bent 

 completely back upon itself and then turned inward at a right angle 

 like a sickle, with a large accessory tooth on the outer or convex 

 side. Neither basal joint or claw shows any plumose setae, but the 

 latter has a small smooth bristle on the ventral surface of the first 

 bend. 



The first legs have very broad and flattened rami, the exopod 

 one-jointed and as long as the two-jointed endopod; the joints of 



