MEXICAN, CENTRAL AMERICAN, AND CUBAN CAMBARI 7 
liform. Those of the fourth pereiopod very strongly devel- 
oped, swollen and inflated, tapering to a blunt point; cowopo- 
dite of third pereiopod with a semicircular, elevated, compressed 
tubercle, that of the fourth pereiopod with a strong, triangular 
spine, directed outward ; that of the fifth pereiopod with a small, 
spiniform tubercle below genital opening, directed downward. 
a b 
Fic. 4. Cambarus wiegmanni Erichson. First pleopod (right side) of male 
(I). @, outer view; 4, inner view. Enlarged about three times. 
First pleopods (Fig. 4) rather long and slender for the sub- 
genus Caméarus, reaching to the coxopodites of the second perei- 
opods, almost straight, very slightly curved; truncated at the 
tip, with three horny teeth, of which the outer one is compressed 
and truncated, crescentic in shape; the inner tooth is. broadly 
triangular, and the anterior is short and spiniform,' the inner 
part of this organ terminating in an almost straight spine, which 
is only slightly directed outward, and is slightly longer than the 
truncated outer part, and has a distinct horny tip. 
Measurements: ‘Total length 60 mm.; carapace 29, anterior 
part of carapace 18.5, posterior 10.5; width of areola 1.75; 
abdomen 31; length of hand 25.5, width of palm 9.5 (Erichson 
gives the following figures: total length 52 mm., length of 
hand 17 mm., width of hand 6.5 mm. Hagen gives 66 mm. 
as total length.) 
Comparing the present male with the description of the spe- 
1This latter one seems to belong to the inner part; but I suspect strongly 
that such is the case also in other species of the subgenus. The homologies of 
the sexual organs of Caméarus are altogether not well understood, and urgently 
need a more close study. 
Proc. Wash. Acad. Sci., May, 1906. 
