CAMBARUS. 21 
from Camden, a town near the Wateree River, Kershaw Co., S.C. Com- 
pared with Girard’s C. aeu/us, from farther south, the rostrum is longer, with 
longer acumen ; carapace smoother, although granulated on the branchial 
regions ; lateral thoracic spine prominent ; antennal scale longer and much 
narrower ; hand longer, more cylindrical, the squamous tubercles not tend- 
ing to form a definite line of teeth on the inner margin, as in C. aeutus. 
Harlan says, “ All the crawfish which I have seen from the Southern States 
(and I have received specimens from New Orleans and South Carolina) are 
of the same species with that now described.”* It is probable that he 
included in this species not only C. aculus, but also other allied species, as 
C. troglodytes, &e. 
Among specimens collected for the U.S. National Museum by Col. M. M. 
McDonald in the neighborhood of Columbia, 8. C., (a city thirty-two miles 
southwest of Camden, in the same river basin,) are several which nearly 
resemble Harlan’s type. They are younger, and the males are all of the 
second form, with small chelea. The antennal scale is somewhat broader 
than in Harlan’s specimen. Lateral thoracic spine well developed. The 
largest male is 3{ inches in length, chelipeds 2% inches. 
In the collection of Butler University, Irvington, Ind., there is a first 
form male of the same species from the Saluda River, 8. C., collected by Prof. 
D.S. Jordan. The Saluda River unites with the Broad River at Columbia 
to form the Congaree. The chelipeds have been lost. The antennal scale 
is somewhat broader than in Harlan’s type, but in other respects, including 
the form of the anterior abdominal appendages, it agrees with it. Length, 
3 inches. 
In specimens from the low country of North Carolina, Maryland, and New 
Jersey, the rostrum narrows nearer the base, and the hand is closely set 
with ciliate squamous tubercles. In some individuals from North Carolina 
the cardiac region of the carapace is shorter in proportion to the anterior 
portion than in the ordinary form (less than one half the distance from tip of 
rostrum to the cervical eroove). 
Cambarus acutus of Girard, from the South and West, is a larger form, 
with quite a differently shaped hand and rostrum and a shorter abdomen ; 
but after a careful study of a very large number of specimens from the 
Atlantic and Gulf States and the Mississippi Valley, I am inclined to con- 
sider them forms or varieties of one species. The male sexual appendages 
* Trans. Amer. Philosoph. Soe., ILI. 465. 
