MUSEUM OF COMPARATIVE ZOOLOGY. 163 



Family LITHODID^. 



Rhinolithodes cristatipes, sp. nov. 



The carapace is subtriangular in outline, its surface devoid of setae, but 

 covered with low squaniiforni tubercles ; the whole gastric area is raised into 

 a conical prominence ; there is also a prominent crescentic rounded ridge on 

 each branchial region , enclosing the cardiac area in a deep fossa open only 

 behind. The rostrum is straight and conical, with a vertical plate projecting 

 below from the proximal half down between the eyestalks; this plate is 

 toothed anteriorly but does not reach forward nearly to the tip of the rostrum. 

 The antero-lateral margin of the carapace is five-toothed; the second, third, 

 and fourth of these teeth give rise to long thread-like cilia. There is another 

 tooth at the angle between the postero-lateral and posterior margins ; posterior 

 margin straight. The upper surface of the eyestalk is covered with small 

 tubercles and a blunt spine projects over the cornea. The movable scale of the 

 antenna is spiniform and bears two blunt spinules on the outer side and two 

 smaller ones on the inner. The chelipeds are unequal (the right being the 

 larger); coxa granulated, setose on the lower inside margin; lower margin of 

 the merus armed with three or four blunt teeth, superior margin toothed, inter- 

 nal distal border setose, external distal border forming a bilobed crest; outer 

 face of carpus squamous, margins cristate, the internal crest expanded and cut 

 into setiferous lobes ; propodus tuberculated without, smooth within, toothed 

 and setose on superior margin; immobile finger, as well as the dactylus, exca- 

 vated within, setose ; the larger claw has blunt teeth on the fingers, while the 

 fingers of the smaller claw have nearly straight cutting edges. The ambula- 

 tory appendages have cristiform anterior margins from the merus to the propo- 

 dus inclusive ; the crest of the carpus is entire, but that of the merus is bilobed, 

 of the propodus trilobed; the posterior margins of these appendages are den- 

 tate and more or less setose, the dactyli are provided with curved acute black 

 tips, and with pencils of hair especially on anterior margins. The abdomen 

 is indurated, with three rows of tuberculated plates. 



Length of carapace, 16.5 mm.; breadth, 16.5 mm. 



Station 3354. 322 fathoms. 1 male. 



I have seen neither specimen nor figure of the type of this genus, Rhinoli- 

 thodes ivossnesenskii Brandt, from the coast of Alaska, and the specimen above 

 described possibly does not belong to the same genus. Brandt's generic 

 diagnosis (Bull. Phys.-Math. Acad. Sci. St. Petersbourg, VII. 174, 1849) 

 appears to include specific as well as generic characters. The specimen above 

 described conforms to Stimpson's diagnosis of the genus (Proc. Acad. Nat. Sci. 

 Phila., 1858, p. 231): "Abdomen scutis triseriatis obsessum. Antennartim 

 aciculum margine spinosum. Pedes mediocres." 



VOL. XXIV. — NO. 7. 2 



