132 BULLETIN OF THE 



somewhat regularly in size to a point near the anterior extremity, where 

 they gradually diminish again. < >n the outer edge of the hand there are 

 four or five large and about eleven small teeth alternating by threes with 

 the larger ones. The fingers are white in color, and not so much bent 

 downwards as is usual in the genus. Ambulatory feet long, slender, 



naked, and unarmed, or will ly obscure indications of teeth on the 



ineros-joint. 



Dimensions of a male: Length of carapax, 0.45 ; breadth, 0.50 ; propor- 

 tion, 1 : 1.11 ; length of ineros-joint of cheliped, 0.55 inch. 



In a male specimen of what is probably a variety of this species, dredged 

 off Conch Reef, the hands arc shorter than in the typical form, and the 

 rostrum is not narrowed toward the extremity, and is devoid of marginal 

 teeth. These differences are certainly important ones, but the specimen 

 accords so well with the type in all other characters that I can scarcely 

 believe it to he distinct. 



The species lias some resemblance to /.. mediterraneus Roux, hut differs 

 in the smaller and less numerous marginal teeth of the carapax, and in the 

 unarmed ambulatory feet. 



Off the Marquesas, February 10, 1869. Cast No. 3. 40 fathoms. 



Off Carysfort Reef, March 21, 1869. Cast No. 7. 40 



Off Conch Reef, March 21, 1869. Cast No. 1. 40 



Off Conch Reef, May 11, 1869. Cast No. 3. 49 



Solenolambrus nov. gen. 



This name is proposed for a well-defined group of Parthenopidae, allied 

 to Lambrus, of which I have before me three species, the only ones as yet 

 known, all of which ate new to science. 



The carapax is pentagonal, and more or less broader than long. The 

 posterior side of the pentagon is much the shortest, and the other four 

 sides are about equal. The margin is acute on all sides, forming a slight 

 crest. The upper surface is naked, -lossy, strongly convex, and bears 

 four protuberances, one gastric, one cardiac, and two branchial. The gas- 

 tric and cardiac protuberances are more or less triangularly pyramidal, and 

 the branchial protuberance i^ armed with an acute ridge, running obliquely 

 to the postero-lateral margin of the carapax. The frontal region is slightly 

 convex, and there is no protuberance on the orbital region. 'I he rostrum 

 is short and blunt, or faintly tridentate. The orbits are round, with the 

 upper margin entire and smooth. The basal joint of the external antenna' 

 is about as long a- the next joint ; it may he either longer or shorter. 

 The epistome is concave. From the antero-external angle of the buccal 

 area a sharp, elevated, crenulated ridge extends to the outer base of the 

 cheliped, separating the concave pterygostomian from the subhepatic 



