Cast No. 



4. 



36 fathoms. 



Cast No. 



1. 



40 



Cast No. 



2. 



45 " 



Cast No. 



5. 



60 



Cast No. 



13. 



68 " 



MUSEUM OF COMPARATIVE ZOOLOGY. 155 



Chelipeds rather stout; outer surface strongly rugose with punctate 

 tubercles and pits ; hand with four teeth on the superior crest. Ambula- 

 tory feet (except dactyli) naked, compressed, and crested above and be- 

 low ; crest of meros-joint with a row of pits along the posterior side, giving 

 it a plicated appearance ; last three joints with another crest on the pos- 

 tero-superior surface ; dactyli stout, densely pubescent below. 



Dimensions of a male : Length of carapax, 0.56 ; breadth, 0.59 inch ; 

 proportion, 1 : 1.054. 



West of Tortugas, January 16, 1869. 



Off Conch Reef, March 21, 1869. 



Off French Reef, March 21, 1869. 



Off Carysfort Reef, March 21, 1869. 



West of Tortugas, January 16, 1869. 



Family LEUCOSIDAE. 



Subfamily ILLIINAE. 

 No attempt has yet, I believe, been made to separate the Leucosidae 

 into subfamilies. The existence of the group which I have here named 

 Iliinae seems to be sufficiently well indicated by tangible characters, such 

 as the long, slender chelipeds, and the two-notched extremity of the 

 pterygostomian channel. 



Iliac an tha nov. gen. 



Closely allied to Ilia, but having three spines (one median) at the pos- 

 terior extremity of the carapax, instead of four tuberculiform teeth. From 

 Persephona, Myra, and other allied genera of Leucosidae, it differs in the 

 peculiar conformation of the hands, which are twisted, so that the fingers 

 open in a vertical instead of a horizontal plane. 



The pterygostomian channels at their anterior extremities project con- 

 siderably beyond the orbits. The abdomen in a young male, the only 

 specimen of that sex I have seen, is seven-jointed, none of the joints be- 

 ing soldered together. 



The species of Ilia, the nearest ally of this new genus, are confined to 

 the Mediterranean Sea. 



Iliacantha subglobosa nov. sp. 

 Carapax subglobose, smoothly and evenly convex, and unarmed, except 

 at the posterior extremity, where there are three spines, similar in position 

 to those of the species of Myra and Persephona, the middle one being long 

 (equalling in length one seventh that of the carapax) and curved upward, 

 and the lateral ones flattened, triangular. The hepatic region is consider- 

 ably swollen, but entirely unarmed, and is bounded posteriorly by a depres- 



