1905.] ORTMANN— AFFINITIES OF CAMBARUS. 107 
C. chapalanus and montezume still remain in the original home of 
the genus, although they have changed a good deal, C. shufeldti 
seems to be an early emigrant, which, however, has not much 
changed. Further investigations in this subgenus are much needed. 
Subgenus: Faxonius (Type: C. “mosus).* 
This subgenus corresponds to Faxon’s fourth group, with the 
addition of C. pellucidus. As regards the latter species, which 
Faxon places with his first group, apparently chiefly on account of 
the presence of hooks on the third and fourth pereiopods in the 
male, it is easy to see that the sexual organs do not agree with the 
blandingi-type. Faxon himself says (1885, p. 42), that they are 
very simple, and generally admits that this species unites characters 
of different groups. Looking at the figures of the sexual organs 
given by Hagen (Ill. Cat. Mus. Harvard, 3, 1870, pl. 1, f. 68-71), 
and! Hay CP. U.S) iMus., 16, 1893; pl.’ 45, f.. r1—14) 2b fail! to 
see any similarity to any of the species of the subgenus Caméarus, 
but their shape approaches rather closely that of some species of 
Faxon’s fourth group, namely: C. “mosus, indianansis and sloanet. 
Indeed, in C. pellucidus this organ is different from any one of 
these, but it agrees with them in the more or less straight and 
simple form, with the outer and inner parts separated at the tips 
for a short distance ; there is also no trace of a terminal truncation. 
The rostrum and the chelz are rather primitive in C. pel/ucidus, 
while carapace and areola are peculiar, which is possibly a char- 
acter due to the subterranean life (see Faxon). 
If we place C. pel/ucidus with the species of the fourth group 
named above, it loses its isolated position also with reference to 
the geographical distribution: it is found in a region (Kentucky 
and southern Indiana), where at least two of the above species are 
also found: C. ¢mdianansis and sloanet. 
I think, that C. pe//ucidus is a rather primitive form, connecting 
the subgenus Faxontus with the more primitive forms of Caméarus 
1 Astacus limosus of Rafinesque has been considered by all authors (Girard, 
Hagen, Faxon) as very probably identical with 4. affints of Say. Although 
Rafinesque’s description is very poor, the locality given (‘‘ muddy banks of the 
Delaware near Philadelphia”) renders it absolutely certain that C. effin?s was 
intended. There is no other species on the banks of the Delaware but this, and it 
is so abundant there, that it even attracts the attention of the casual observer. 
Thus I do not see why the older name of Rafinesque should not be restored. 
PROC. AMER. PHILOS. SOC. XLIV. 180. H. PRINTED JULY 28, 1905. 
