MUSEUM OF COMPARATIVE ZOOLOGY. 157 



exognath of the outer maxillipeds straight instead of curved. From Ilia 

 and Iliacantha it differs in its chelipeds, the fingers of which open in a 

 horizontal plane. From Persephona it differs, among other characters, in 

 the basal joint of the antennulae, which is indurated and crested. The 

 anterior extremity of the pterygostomian channel does not reach beyond 

 the orbits. All the joints of the male abdomen are soldered together, ex- 

 cept the terminal one. 



The species of Myra, the nearest ally of the new genus, are all, as far as 

 known, inhabitants of the East Indian and Australian seas. 



Myropsis quinquespinosa nov. sp. 



Body and chelipeds everywhere granulated, above and below. Carapax 

 subglobular, regularly and evenly convex, as in Iliacantha subglobosa ; in- 

 testinal and cardiac regions only defined, and defined by rather deep 

 furrows on either side ; hepatic region not swollen ; cervical sulcus obso- 

 lete ; granules of the surface equal in size and distributed with great 

 regularity, being distant from each other by a space equal in width to two 

 or three times their diameter. Lateral margins of carapax regularly 

 arched. Of the five posterior spines, the median one is situated on the 

 intestinal region ; the intermediate ones are but little smaller than the 

 median one, and are placed at a lower level, occupying the postero-lateral 

 angles of the carapax ; the outer ones, placed on the branchial region over 

 the insertion of the posterior feet, are small, only one third as long as the 

 median spine. There is also a small spine at the middle of the lateral 

 margin, and one on the hepatic region. The frontal teeth are obtuse, and 

 not very prominent. Chelipeds cylindrical ; meros more than two thirds 

 as long as the carapax, and covered with granules as large as those of the 

 carapax, but densely crowded ; granules of hand smaller, but also densely 

 crowded ; fingers longer than the palm, and armed within with very 

 minute and acute teeth varying in size. Ambulatory feet naked (except 

 the dactyli), cylindrical, and partly microscopically granulated ; those of 

 the first pair one sixth longer than the carapax. 



Dimensions of a male: Length of carapax, spines included, 0.72; 

 breadth, 0.58 ; length of cheliped, 1.25 inch. 



Off Tennessee Reef, May 7, 1869. Cast No. 1. 21 fathoms. 

 May 11, 1868. Cast No. 5. 82 " 



Callidactylus noy. gen. 



Carapax rounded, nearly as broad as long, regularly convex, except 



near the anterior margins ; hepatic region well defined, protuberant, and 



toothed ; posterior extremity armed with three spines, as in Persephona, 



etc. Front short ; basal joint of the antennula? not indurated. Orbit 



