CRAYFISHES. 



399 



to separate C monongalensis from C. carolinus, viz., the uniserial disposition 

 of the spines on the lower face of the merus of the chehped, and the colour. 



So, with a broader overlook of the geographical variations of these interest- 

 ing forms it would seem to be more logical to consider C. carolinas Erichs., C. 

 dubius Fax. and C. nionongalcnsis Ortm. as three geographical races, or subspecies 

 of one species. The three subspecies may be distinguished by means of the sub- 

 joined key: — 



Lower face of nienis 

 with only one row of spines 

 developed. Colour, blue . 



C. carolinus innnnnf/iileiisiii (Ortm.) 



Lower face of merus 

 with two rows of spines 

 developed. Colour, red. 



Margins of rostrum distinctly con- 

 vergent; outer margin of hand 

 rounded, not serrated; more than 

 one sjiine on inner margin o! the 

 hand.. ...... 



Rostrum broader with nearly par- 

 allel margins; outer margin of 

 hand subserrate; only one spine 

 on inner margin of the hand . 



C. carolinus carolinus Erichs. 



C. carolinus dubius Fax. 



The geographical range of C. c. monongalensis, so far as it has been worked 

 out by Dr. Ortmann, has been given above. More exploration is needed to 

 elucidate the dispersal of the typical C. carolinus. The type locality is near 

 Greenville, Greenville Co., S. C. The specimen in the U. S. National Museum, 

 collected by James Mooney and described above, came from Swain or Jackson 

 Co., western North CaroUna. Ortmann (Mem. Carnegie Mus., 2, p. 397) men- 

 tions some specimens in the Academy of Natural Sciences of Philadelphia, 

 collected by Prof. J. P. Moore at Blowing Rock, Watauga Co., N. C, which 

 have a narrower rostrum than C. c. dubius, and are therefore pi'obably C. c. 

 carolinus. 



Specimens cqllected by Mr. H. G. Hubbard at Pennington's Gap, Lee Co., 

 Va. (M. C. Z., No. 3,489) and by myself at Cumberland Gap, at the junction 

 of the three states of Virginia, Kentucky and Tennessee (M. C. Z., No. 3,594) 

 are too young to determine subsi^ecifically with assurance, but they appear to 

 be C. c. dubius. The form spread over the southwestern parts of West Virginia, 

 as has been pointed out (p. 397) is more or less intermediate Ijetween carolinus 

 and dubius, while the pure C. c. dubius has been reported from Westmoreland, 

 Fayette, and Somerset Cos., Pa., Garrett Co., Md., and Preston, Tucker, and 

 Mineral Cos., W. Va. 



