416 A HISTORY OF RECENT CRUSTACEA 



Bopyrus (?) al]jhei, Fritz Miiller, in a Brazilian Air- 

 flieus sp. 



The Zeiixo alphei^ Kossmann, 1872, described as an 

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

 tioned here, and perhaps the Prosthete cannelee of Hesse, 

 1861, belongs to this genus. 



Frobojjynis, 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 tvvo-brancbed 

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

 tuberculiform pleopods. This freshwater geuus is con- 

 sidered to represent an ancestral less degraded form of 

 Bojpyrus. 



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

 natus, Olivier, which in the Philippines inhabits streams up 

 to 4,000 feet above the sea-level. 



Probopyrus palctmoneticdla (Packard), in Palcemonetes 

 vulgaris, Stimpson, of North America. 



Prohopyrus Giardi^ Max Weber, 1892, on Palcemon 

 placidus, 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 virhii (Walz), 1881, on ' Virhius ' viridis, Otto. 



Bopyrina ocellata (Czerniavsky), 1869, on ' Virhius^ 

 Heller. 



Bopyrina nitescens, Giard and Bonnier, 1890, on Aihanas 

 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 liippolytes^ Giard and Bonnier, 1890, on Bip- 

 polyte Cranchii, Leach (?). This species also appears to be 

 at present only nominal. 



With regard to the genus Virhius, the reader may refer 



