ISOPODS OF NORTH AMERICA. 537 



pair of simple elongated uropoda, equaling in length the dorsal 

 branches of the pleopoda of the other abdominal segments. 



The marsupium is composed of five pairs of lamella?, the lamellae of 

 the fifth pair being very large, and occupying almost half of the 

 ventral side of the thorax. 



Male unknown. 



Only one specimen was collected by Dr. G. Brown Goqde at the 

 Bermudas in 1876-77. The parasite was found attached to Clibanarius 

 tricolor. 



Type in the Peabody Museum, Yale University. 



This genus differs chiefly from Stegophryxus Thompson, to which 

 it is closely related in having the pleopoda of the fourth and fifth 

 abdominal segments biramous instead of triramous; in having the 

 uropoda long and leaf-like, similar in shape and size to the branches 

 of the pleopoda, while in Stegophryxus hyptius, the type species of 

 the genus, the uropoda are small, rounded, and knob-like, with a 

 minute conical prominence between them; and in not having the sixth 

 thoracic segment great! 3^ longer than the others. 



9O. Genus BATHYGYGE Hansen. 



Body of female asymmetrical, the abdomen being turned to one 

 side in a marked degree. Epimeral plates, consisting of large oval 

 lamella?, anteriorh' very much produced and attached near the inner 

 posterior margin. 



Segments of the abdomen distinct; lateral parts or pleural lamellae 

 not developed. Abdomen small. 



The pleopoda consist of five pairs of double-branched lamella?, the 

 two branches being unequal in size, and arising from a common 

 peduncle attached to the lateral margin of the segment. 



The uropoda are double-branched. 



Male with the abdominal segments fused; abdomen ovate in outline. 



Pleopoda and uropoda absent. Segments of thorax distinct. 



Branchial parasites. 



BATHYGYGE GRANDIS Hansen. 



Bathygyge grandis HANSEN, Bull. Mus. Coinp. Zool. Harvard College, XXXI, 

 1897, pp. 122-124, pi. vi, figs. 2-2e. RICHARDSON, Proc. U. S. Nat. Mus., 

 XXI, 1899, p. 869; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 338. BONNIER, 

 Travaux de la Station Zool. de Wimereux, VIII, 1900, pp. 291-292. 



Locality. Off Acapulco, in the branchial cavity of Glyphocrangon 

 spinulosa Faxon. 



"Only a male, and the posterior part of a female have been sent 

 to me. 



"(a) Female. The rudiment consists of the posterior part of the 

 thorax, bearing three legs on one and two on the other side, and the 

 abdomen. 



