CAMP.AEUS. 63 



(Nense River basin). It is doubtfully reported from South Carolina and 

 Georgia ; but its place seems to be largely taken in those States by the 

 nearly related C. httirmtniis. Lake Superior and Osage River are isolated 

 Western localities from which C. Barlonii is reported. 



As a rule, C. Brlouii prefers the cooler waters of mountain regions or 

 uplands, while the clay bottoms and marshes, both on the east coast and in 

 the Western prairie country, afford the related C. Dioyencs. According to Dr. 

 C. C. Abbott, C. Bartonii in the neighborhood of Trenton, N. J., burrows in 

 the muddy banks of ditches, small streams, and of the Delaware River. He 

 says: " The burrows of Ctunbarus Bartonii, so far as we have discovered them, 

 have all been in the banks of the smaller streams and meadow ditches (and 

 occasionally a colony of burrows in the river bank, where peculiarly favor- 

 able), a little below the usual water line." It is not, however, pre-eminently 

 a burrowing species, like its cousin, C. Diogenes, being more commonly found 

 under the stones in clear streams and in springs. In the U. S. National 

 Museum are young specimens found in a spring in Clarke Co., Va., the 

 temperature of whose water is 67 F. The observations of Dr. Godman* 

 upon the habits of a burrow-dwelling species probably relate to C. Bartonii. 



According to Dr. John Sloan, of New Albany, Ind., C. Bartonii is found 

 in ponds and still water in that locality, C. Sloanii being the common form 

 in the running streams. 



The well-known occurrence of C. Baiionii with well-developed eyes in 

 the Mammoth Cave of Kentucky is mentioned on p. 41. Mr. A. R. Crandall 

 has also collected it in Lineville Cave, near Blountsville, Tenn. 



As might be expected in a species with such an extended geographical 

 range, C. Bartonii is subject to considerable variation. The variations affect 

 especially the rostrum, areola, antennal scale, epistoma, and chelte. In the 

 common Eastern form, the rostrum is short, broad, nearly plane above, the 

 sides nearly parallel from the base to near the tip, where they suddenly 

 converge to form the short acumen. The antennal scale is narrow. The 

 areola is rather narrow, with two or three longitudinal rows of impressed 

 dots. The chelae are coarsely punctate, the internal margin of the hand sub- 

 tuberculate, the fingers gaping at base. To the westward, in the Alleghany 

 Mountain region of Virginia, and in the Ohio River basin, specimens are 

 found in which the rostrum is longer and narrower, the margins converging 



* Rambles of a Naturalist, with a Memoir of the Author, Dr. John D. Godman, p. 42. Philadelphia, 

 1859. (Republishcd from " The Friend.") 



