go 
1888. Nika, Bate, Challenger Macrura, Reports, Vol. XXIV., 
Pp. 525: 
1890. Nika, Ortmann, Zool. Jahrb., Vol. V., pp. 461, 528. 
1893. Nika, Stebbing, History of Crustacea, p. 229. 
1893. Processa, Sharp, Proc. Acad. Philad., p. 124. 
1896. Processa, Ortmann, Zool. Jahrb., Vol. IX., p. 424. 
1901. Processa, M. J. Rathbun, Bull. U.S. Fish. Comm. for 
7900; Vol vii.) py -r04: 
1904. Processa, M. J. Rathbun, Decap. Crust N.W. Coast N. 
Amer., p. I10. 
Desmarest claimed priority for Risso’s name, on the feeble 
ground that Risso had formed the genus under the name of 
Nika in 1813, though he did not publish it until 1816. Bell 
says that Risso “ had, a short time before Leach’s publication, 
given to the genus the name of Nzka, of which Leach was not 
aware at the time. Risso’s name must, therefore, be re ained, 
on the ground of priority of publication.” But that is precisely 
the ground which it has now been proved not to occupy. 
The genus is at present fairly well distinguished by the short 
rostrum, the mandibles without cutting-edge or palp, the 
unsymmetrical first peraeopods, one member being chelate, 
the other simple, and the unequal second peraeopods, of 
which one is much longer than the other, though both alike 
are chelate, with multiannulate fifth joint. 
Miss Rathbun has, however, discovered that among specimens 
from the same locality some are occasionally to be found which 
have both members of the first pair of legs chelate, though 
not otherwise appreciably different from those in which these 
limbs are unsymmetrical. In other respects also she finds 
the species most variable, as in ‘length of rostrum, size and 
shape of the eyes, length of second joint in the first antennae 
compared with that of the third joint, and length of the antennal 
scale compared with that of the trunk of the carapace. Under 
these circumstances the discrimination of species must be 
subject to much uncertainty. Risso’s Nika vaniegata and 
N. sinuolata have apparently not been rediscovered. De Haan 
distinguishes N. edulis from his N. japonica, on the ground 
that the former has the body less elongate, the rostrum carinate, 
longer than the eyes, and the last two joints of the third 
maxillipeds together equal to the antepenultimate. In Pro- 
cessa canaliculata (N. edulis), however, the rostrum is prob- 
ably seldom longer than the eye. Miss Rathbun says, “ The 
rostrum may be half as long or nearly as long as the eye.” 
The third maxillipeds of an English specimen have the last 
two joints together, as compared with the preceding joint, 
