CAMBAEUS. 21 



from Camden, a town near tlie Wateree River, Kershaw Co., S. C. Com- 

 pared with Girard's C. acidits, from farther south, the rostrum is longer, with 

 longer acumen ; carapace smoother, although granulated on tlie 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. acutus. 

 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 ucutus, but also other allied species, as 

 C. iroglodijies, &c. 



Among specimens collected for the U. S. National Museum by Col. M. M. 

 McDonald in the neighborhood of Columbia, S. 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 cliela3. The antennal scale is somewhat broader 

 than in Harlan's specimen. Lateral thoracic spine well developed. The 

 largest male is 3j inches in length, chelijjeds 2| inches. 



In the collection of Butler University, Irvington, Ind., there is a first 

 form male of the same species fi'om the Saluda River, S. C, collected by Prof. 

 D. S. Jordan. The Saluda River unites Avith 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. 



Li 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 tlie distance from tip of 

 rostrum to the cervical groove). 



Cambarus aciitm 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 Valle}*, I am inclined to con- 

 sider them forms or varieties of one species. The male sexual appendages 



* Traus. Aiiier. Philosopli. Soc, III. 465. 



