175 



scarcely broader than the 2 succeeding- pairs; 4tli pair much more deep than 

 hroad, lower edge shorter than the hind margin. Metasome and the posterior 

 part of niesosome distinctly keeled dorsally. Last pair of epimeral plates of 

 metasome produced at the lateral corners to a spiniform projection, posterior 

 edge evenly convex in tlie middle. First segment of urosonie with a very 

 slight dorsal carina. Corneal lenses distinct, the lower pair placed within a 

 small sinus of the inferior edges of the cephalon, at a short distance from 

 the lower corners of the front ; underU-ing pigment well-defined and Ijright 

 red. Superior antennae in female about 8 times the length of the cephalon, 

 and considerably projecting beyond the peduncle of the inferior ones, flagellum 

 2 and a half times as long as the peduncle, and composed of about 30 arti- 

 culations clothed posteriorly with fascicles of slender setse. Inferior antennae 

 twice the length of the superior, witli tlie 2 outer joints of the peduncle 

 nearly equal-sized. Both pairs of gnatlio]i()da rather slender, but especially 

 the posterior ones; propodus in the former a little shorter than the carpus, 

 and oblong oval in form ; in the latter about half as long as the carpus, and 

 sublinear. Dactj'lus of the anterior pairs of pereiopoda very slender and 

 considerably exceeding in length the 2 preceding joints combined. The 2 

 succeeding pairs, with tlie projiodal joint produced beyond the short recurved 

 dactylus, to a compressed setiferous lobe. Last pair of pereiopoda with the 

 basal joint considerablj- exceeding in length the remaining part of the leg, 

 posterior expansion somewhat irregular in form, obliquely truncated, and 

 strongly rounded at tlie inferifir ('orner, which reaches almost to the end of 

 the meral joint; carpal joint rather broad, nearl}- heart-shaped, and considerably 

 projecting anteriorlj', pro])odal joint very narrow, and shorter than the 2 

 preceding joints combined, dactylus narrowly lanceolate, and exceeding half its 

 length. Tjast i)air of uropoda with the rami lanceolate, twice as long as the 

 basal part, and fringed with ciliated bristles, besides a few spinules. Telson 

 oblong and quite naked, excepting for a small apical denticle on each side. Body 

 semipellucid, with a faint yellowish tinge, and mottled with oi'ange and 

 pinkish pigment. Length of adult female reaching 25 mm. 



Bemarl-ti. — This is the first described species of the genus, and is 

 readily recognized from most other species, not onlj- by its lai'ge size, bvxt 

 also liy several other well-marked characteristics, thus by the distinctly keeled 

 ])osterior part of the hody, by the form of the cephalon and the last pair of 

 oi)imeral plates of metasome; furthermore, by the mutual length of the antennse, 

 and 1)3' the structure of the last pair of jjereiopoda. The Amjxlisca ivgens 

 of Stimpson, as described by Sp. Bate, would seem to be this species, at least 

 to judge from its large size. The two imperfectly described species, named 

 bji- Boeck as A. diihia and propinqra, must be cancelled, as I have found, on 



