MUSEUM OF COMPARATIVE ZOOLOGY. 141 



Dimensions of a male: Length of carapax, 0.18 ; breadth, 0.26 inch; 

 proportion, 1 : 1.44. 



This species approaches somewhat C. levissimus Dana, of the Sandwich 

 Islands, but differs from that and all other known species in its smooth, 

 oval, convex carapax and the obsolescence of the anterolateral teeth. 



Found on the reef at Cruz del Padre, Cuba; two specimens, a male and 

 a female. 



Family ERIPHIIDAE. 



Subfamily OZINAE. 



Pilumnus aeuleatus II. M.-Edw. 



Cancer acuh at us Say, Jour. Acad. Nat. Son, Philad., I, 449. 



Pilumnus aeuleatus II. Milne-Edwards, in Gueein, Iconog. du R'egne 



Anim., Crust., pi. iii, tig. 2; and Ilist. Nat. ties Crust., I, 420. Gibbes, 



Proc. Am. Assoc Adv. Sci., 1850, p. 177. 

 A young specimen of this species was collected at the Tortugas. I find 

 no note of the depth of water at which it was taken. 



Pilumnus caribaeus Desb. et Schr. 



Pilumnus caribaeus Desbonne et Schramm, Crust, de la Guadaloupe, p. 32. 



The specimens which I have referred to the above species differ from P. 

 aeuleatus in having the anterior spine of the three principal ones of the 

 anterolateral margin bifid, and in the shorter and more numerous spines 

 of the frontal margin. 



Found on the reef at Cruz del Padre, Cuba, and at Key West in from 

 2 to 5 fathoms. 



Pilumnus noridanus nov. sp. 



This species belongs to the same group with P. arvhatus, and bears a 

 close resemblance to it. It differs in its narrower carapax, which is 

 covered with a dense, short pubescence, with a few longer hairs, a trans- 

 verse series of which, across the frontal region, forms a somewdiat con- 

 spicuous feature. Below the ciliated line, the frontal region is naked, 

 and its margin is unarmed : its lobes are not strongly and evenly project- 

 ing as in aeuleatus, hut are most prominent within, near the median sinus. 

 The orbits are unarmed above, but have eight or ten spiniform teeth on 

 the margin below, which teeth are far shorter than in aeuleatus. The 

 subhepatic tooth or tubercle is small and inconspicuous, and the surface of 

 the subhepatic region is not perceptibly granulated. There are no spines 

 on the hepatic region above. In the chelipeds the entire outer surface of 

 the greater hand is tuberculated. The ambulatory feet are armed with 

 spines as in acuh at us. 



