BOPYRIM. 223 



ISOPODA . BOP YRIDJE. 



NORMALJA. 



Genus GYGE, CORN ALIA AND PANCERI. 



Mem. Acad. Reale di Torino, Ser. 2, t. 19 (1861), p. 85. 



Male. Cephalon as broad as first segment of the pereion. 

 Pereion long and narrow, segments subequal in length. Pleon 

 short and broad, segments distinct and subequal in length with 

 those of the pereion. Eyes small and situated at the posterior 

 part of the cephalon; second pair of autennte well developed. 



Female. Oval, anteriorly slightly unsymmetrical. Pereion, 

 having the segments subequal, except the first two. Pleon having 

 the segments distinct and subequal with those of the pereion. 

 Antennae rudimentary. Branchial appendages consisting of a 

 series of small single sacs attached within the ventral lateral 

 extremity of the several segments of the pleon, and a series of 

 transverse folds between them. Posterior pair of pleopoda 

 slightly developed. 



THIS genus is certainly near Bopyrus, but differs from 

 it in important structural conditions. It must also be 

 very closely allied to the genus Bopyroides of Stimpson, 

 which that author has formed for those species that 

 agree in shape and structure with Bopyrus, but differ in 

 their branchial features, in having " merely fleshy ridges 

 instead of laminae." 



From the female Bopyrus and therefore also from Bopy- 

 roides this genus differs in shape, being roundly oval, and 

 not having the pleon narrower than the pereion ; moreover, 

 in this genus the segments are distinct, in which it coin- 

 cides with Stimpson's description of Bopyroides, whereas 

 in Bopyrus they are all fused together in the central 

 dorsal axis. Bopyrus, also, is unsymmetrical throughout, 



