MUSEUM OF COMPARATIVE ZOOLOGY. 131 



spine placed beneath and outside of this basal tooth. The chelipeds are 

 shorter, and the lower surface of the hand is always ornamented with 

 several rows of granulated tubercles. The dactyli of the ambulatory feet 

 are covered with a dense velvet-like pubescence, except at the tips. 



Dimensions of a male: Length of carapax, 0.47 ; breadth, 0.45 inch. 

 Of a female, length of carapax, 0.54 ; breadth, 0.56 ; length of meros-joint 

 of cheliped, 0.34 inch. 



Off Sand Key, 



May 11, 1868. 



Cast No. 



2. 



26 fathoms. 



Off Carysfort Reef, 



March 21, 1869. 



Cast No. 



8. 



35 " ' " 



West of Tortngas, 



January 16, 1869. 



Cast No. 



4. 



36 " 



Off Conch Reef, 



March 21, 1869. 



Cast No. 



1. 



40 " 



Off Carysfort Reef, 



March 21, 1869. 



Cast No. 



5. 



60 " 



West of Tortugas,- 



January 16, 1869. 



Cast No. 



13. 



68 " 



Lambrus agonus nov. sp. 



Carapax broader than long, of rounded form, without angles at the sides. 

 Depressions between the regions rather shallow. Surface above every- 

 where minutely tuberculated and granulated. The larger tubercles are 

 somewhat spiniform, and are arranged as follows : Five on the gastric 

 region, of which four are placed in a transverse line across the middle, 

 and one, larger than the others, on the median line behind them ; three 

 in a longitudinal row on the cardiac region ; one each side of the intes- 

 tinal, far apart ; five on each branchial, and one on the hepatic region. 

 From the central cardiac, and from each hepatic tubercle, proceeds on each 

 side a row of granules, forming a V. Antero-lateral margin behind the 

 hepatic region armed with six very small teeth, beneath and behind the 

 posterior one of which there is a short tooth-like crest. The rostrum, 

 though smaller in size, resembles that of L. Pourtalesii in having a slender 

 extremity, but instead of two denticles near the tip, it has two or three 

 denticles near the basal teeth. There are two prominent teeth on the 

 outer side of the orbit, and a minute spine at the summit of the eye. On 

 the sternum, near the base of the chelipeds, there is a conical tubercle on 

 each side. Tooth of the basal joint of the cheliped acutely triangular. 

 On the second joint of the abdomen there is a sharply prominent, bluntly 

 triangular transverse crest, and a tooth on each side ; and on the penult 

 joint there is a crest like that of the second joint, but smaller. 



The chelipeds are very long and slender; upper surface minutely sca- 

 brous, and with an irregular row of tooth-like tubercles which is median on 

 the meros and carpus, but approaches the outer margin in the hand. 

 Edges of the meros and carpus with numerous small irregular teeth. On 

 the inner (superior) edge of the hand there are nineteen teeth, increasing 



