416 A HISTORY OF RECENT CRUSTACEA 
Bopyrus (?) alphei, Fritz Miiller, in a Brazilian Al- 
pheus sp. 
The Zeuxo alphet, Kossmann, 1872, described as an 
external parasite on the head of an Alpheus, may be men- 
tioned here, and perhaps the Prosthéte cannelée of Hesse, 
1861, belongs to this genus. 
Probopyrus, Giard and Bonnier, 1888. In the female 
the pleon has the houndaries 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 Palceemon or- 
natus, Olivier, which in the Philippines inhabits streams up 
to 4,000 feet above the sea-level. 
Probopyrus palemoneticola (Packard), in Palcemonetes 
vulgaris, Stimpson, of North America. 
Probopyrus Giardi, Max Weber, 1892, on Palceemon 
placidus, de Man. 
Bopyrina, Kossmann, 1881. The first antenne 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 antenne are reduced to a rudiment. 
The pleon in both sexes is feebly segmented, in the female 
with short sack-like appendazes, in the male without any. 
The first pair of marsupial plates are colossal, the rest 
rudimentary. 
Bopyrina virbit (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 hippelytes, Giard and Bonnier, 1890, on Hip- 
polyte Cranchit, Leach (?). This species also appears to be 
at present only nominal. 
With regard to the genus Virbius, the reader may refer 
