416 A HISTORY OF RECENT CRUSTACEA 



Bopyrus (?) alphei, Fritz Miiller, in a Brazilian Al- 

 fheus sp. 



The Zeuxo alphei, Kossmann, 1872, described as an 

 external parasite on the head of an Alpheus, may be men- 

 tioned here, and perhaps the Prosthete canneUe of Hesse, 

 1861, belongs to this genus. 



Frohopyrus, Giard and Bonnier, 1888. In the female 

 the pleon has the boundaries of the segments well marked 

 all across the back, and has five pairs of two-branched 

 pleopods. In the male the pleon has five pairs of little 

 tuberculiform pleopods. This freshwater genus is con- 

 sidered to represent an ancestral less degraded form of 

 Bopyrus. 



Probopyrus ascendens (Semper, 1880), in Palcemon or- 

 natus, Olivier, which in the Philippines inhabits streams up 

 to 4,000 feet above the sea-level. 



Probopyrus palcemoneticola (Packard), in Palcemonetes 

 vulgaris, Stimpson, of North America. 



Probopyrus Oiardi, Max Weber, 1892, on Palamon 

 plaoidus, de Man. 



Bopyrina, Kossmann, 1881. The first antennae are 

 relatively strong in both sexes, especially the basal joint, 

 which in the female works upon the skin of the host. In 

 the adult the second antennae are reduced to a rudiment. 

 The pleon in both sexes is feebly segmented, in the female 

 with short sack-like appendages, in the male without any. 

 The first pair of marsupial plates are colossal, the rest 

 rudimentary. 



Bopyrina virbii (Walz), 1881, on ' Virbius ' viridis, Otto. 



Bopyrina ocellata (Czerniavsky), 1869, on ' Virbius' 

 gracilis, Heller. 



Bopyrina nitescens, Giard and Bonnier, 1890, on Athanas 

 nitescens, Leach. The authors think the species may be- 

 long to some genus distinct from Bopyrina, and merely 

 name it to call attention to it. 



Bopyrina hippolytes, Giard and Bonnier, 1890, on Hip- 

 poly te Granchii, Leach (?). This species also appears to be 

 at present only nominal. 



With regard to the genus Virbius, the reader may refer 



