JV^otes on North, American Crustacea. 197 



antennpe with a liigh laminiform crest on each margin, the intervening 

 surface being deeply concave; — these crests converge and join each 

 other at the anterior extremity of the joint, and the moveable part 

 is inserted above the point of juncture. Meros-joint of the external 

 maxillipeds with the anterior angles expanded and prominent as in P. 

 macrodera. Chelipeds with slender hand and long fingers not gaping. 

 Ambulatory feet slender, very hirsute on the exterior half of their 

 length ; first pair stouter than the others, especially in the meros-joint. 

 The erect laminiform expansions of the sternum, which form the sides 

 of the egg-cavity, are high and overlapped by the abdomen when shut 

 down; — at the anterior extremity the lamina is deeply incised in the 

 base, forming two triangular points between the bases of the chelipeds. 

 Length of the carapax in our specimen, O.V ; breadth posteriorly, 0.58 ; 

 length of first pair of ambulatory feet, 2.06; of the posterior pair, 1.28 

 inch. 



This species and the next depart widely from the type in 

 the great slenderness of the ambulatory feet, which, also, are 

 not distinctly prehensile, the thumb-process of the penult joint, 

 even in the posterior pairs, being almost or entirely obsolete, 

 and when present situated below the middle of the joint. These 

 characters render the group at first sight so distinct that we 

 had described it in manuscript as a genus under the name of 

 Podonema, but we are now inclined to doubt the propriety of 

 such a separation and to regard the differences as only those of 

 degree. P. inacrodera is in fact a species intermediate in 

 character between the two groups. 



P. riisei was found at tlie Island of St. Thomas, by A, H. 

 Riise, Esq., after which indefatigable investigator of West 

 Indian JS^atural History we have named the species. 



Podocliela deflexirrons, nov. sp. 



Front and rostrum deflexed ; rostrum not as long as broad. Neck 

 much constricted. Eyes very large. Hepatic tooth abruptly prominent 

 downward. Chelipeds moderate ; lower edge of meros and ischium 



