NO. 1162. JiBA CHYURA COLLECTED B Y THE ALBA TROSS—RA THB UN. 575 



Cliclipeds heavy in the male. Ischium with a tooth on its inner mar- 

 gin ; nieins witli a tiichuitate crest on tlic sni)crior margin. Carpus with 

 surface uneven, a tubercle at the inner angle. Hands broad, compressed, 

 widening distally, inner surface tuberculate; lower margin of ])r()podu8 

 with a sinus near its middle. Dactylns with an acute ui)i)er margin. 

 Fingers gajjing for their basal half. Chelipeds of female much smaller 

 than of male. 



Ambulatory legs cristate as in hicarinata. The crest on the meral 

 Joints has a thin triangular' tooth at the distal end; carpal joints with 

 two triangular crests side by side, diverg(?nt from each oth«;r, and form- 

 iug a cup on the upi)er surface. Propodal joints with a single triangu- 

 lar superior crest, a tubercle on the anterior and posterior surfaces, aud 

 with swellings at the articulation with the dactylns. 



The surface of this crab is covered with a dense, short, vascular 

 pubescence. 



IHmfusions. — Male, station 282S : Lciugth, 13.0 mm.; width, l.'J mm. 

 Male, station 2824: Length, 10.!) mm. ; width, 15.8 mm. Fen)ale, station 

 2825: Length, 14.1 mm.; width, 14.5 mm. Female, station 2828: Length, 

 12.3 mm.; width, 11.5 mm. 



This species is distinguislicd from />. hie(trinat<( by the wider rostrum, 

 with a median emargination instead of a deei> cut, by the shallower 

 postlateral sinuses, by the large protuberance at the middle of the 

 branchial ridge, and by the <louble crest on the carpal joints of the 

 ambulatory legs. 



Types.— ^o. 21574, U.S.N.M. Two males, station 2824, 8 fathoms. 



Disfrihidum. — This species was taken at fonr stations in the southern 

 part of the Oulf of California in 7 to 10 fathoms, stations 2824, 2825, 

 2826, and 2828. 



At two stations outside the (lulf of (JaJifornia were taken two si)eci- 

 mens of Lissa, which appear spe(;i(ically distin(;t from the above and are 

 more closely allied to L. hicarinata. These 1 have named — 



29. LISSA AURIVILLIUSI, new species. 

 (Plate XLI, (ijr. 4.) 



Branchial ridge narrow ; 'po,stIateral mnr</in concave; carpal joints of 

 Jirst three pairs of ambulator}/ Uujs ivlth one crest. 



In this species the male and female are wider than long. The gastric 

 l)rominence is small and angnlar; the obliijue ridj;es leading from it are 

 sharj) and liuely tuberculate, with only a shallow tooth at the middle 

 in place of the round knob in tuherosa, and terminate in a raised tooth 

 at the jiostlatcral angle. The i-ardiac hump is small, and the median 

 ridge extending back from it is narrow. Lateral margins tuberculate, 

 with a shallow tooth at the middle and one farther back. Postlateral 

 margin not sinuous as in the other two Ameri(!an species, but present- 

 ing a single shallow sinus extending the entire length of the margin. 

 Median notch of the front shallow; outer teeth prominent. The cheli- 



