193 



plates very large, gradually expanded distally, tip broadly rounded, and 

 densely fringed with ciliated setse; the 2 succeeding pairs much smaller, and 

 somewhat tapering distally ; 4th pair rather deeply emarginated posteriorly 

 in their upper part, the emargination being denned below by an acuminate 

 lobe. Last pair of epimeral plates of metasorae nearly rectangular, lateral 

 corners not produced. First segment of urosome with a very slight carina 

 dorsally. Ocular lenses distinct and rather large, placed near the upper 

 corner of the frontal part, underlying pigment of somewhat irregular form, 

 partly extending downwards, and of bright reddish colour. Superior an ten use 

 about half the length of the body, 2nd joint of the peduncle not attaining 

 twice the length of the 1st, flagellum two and a half times as long as the 

 peduncle, and composed of about 23 articulations. Inferior antennae scarcely 

 longer than the superior, the 2 last joints of the peduncle about equal-sized. 

 Mandibular palp with the terminal joint as long as the preceding one, and 

 slightly dilated in the middle. Gnathopoda comparatively strong, propodos 

 oval in form, and nearly equal in both pairs. Anterior pairs of pereiopoda 

 with the propodos somewhat curved and gradually tapering distally, dactyl us 

 of about same length; basal joint of 3rd pair fully as broad as it is long, 

 that of 4th pair with the anterior edge strongly curved in the middle, carpal 

 joint in both pairs longer than the 2 preceding joints combined, dactylus not 

 very strong. Last pair of pereiopoda with the basal joint rather narrow, 

 broadest at the base, posterior expansion slightly concave in the middle, and 

 forming below a rather narrow deflexed lobe, scarcely reaching beyond the 

 ischial joint, meral joint rather large, longer than the carpal one, and gradually 

 widening distally, propodal and terminal joints very small, and combined, 

 much shorter than the carpal one. Last pair of uropoda with the rami 

 subequal and foliaceous, fringed (in female) with short bristles, outer ramus 

 having, besides, 4 small denticles. Telson but little longer than it is broad 

 at the base, rounded at the tip, cleft extending far beyond the middle. 

 Body whitish, pellucid, with dark violet intestine shining through the integu- 

 ments. - Adult male much more slender than the female, and having the 

 back distinctly carinated in its posterior part. First segment of urosome deeply 

 impressed dorsally, and exhibiting, behind the depression, a hump-shaped 

 setous prominence. Inferior antennae very slender and elongated, exceeding 1 lie 

 length of the body, and nearly twice as long as the superior ones. Last pair 

 of uropoda with the rami comparatively larger than in female, and fringed 

 with long ciliated setae. Length of adult female 10 mm., of male 11. mm 



Remark*. The present species, the type of the genus, was first 

 detected by Prof. Lilljeborg at Kullen, but, at that time, erroneously identilied 

 with Ampclisca Esclmchti of Kruyer. Subsequently he recognized his mistake, 



25 Crustacea. 



