390 CRAYFISHES. 



margins of the carapace destitute of any marlced angle below the eye. A small 

 spine on each side of the carapace on the posterior edge of the cervical groove. 

 Areola long and broad, I as broad as long, thickly strewn with impressed dots. 

 Anterior process of the epistome triangular, truncated anteriorly in old individ- 

 uals. Chelae large, flattened, internal border furnished with a row of low tuber- 

 cles, with another row of obsolescent ones running along beside them. The outer 

 margin of the chela is ridged, on account of a marked longitudinal depression 

 which runs along the distal part of the palm and the proximal part of the immobile 

 finger. The fingers are long, heavily pitted, meeting only at their tips, leaving 

 a wide gape between them. The carpus is armed with an internal median spine, 

 and a very small internal posterior spine; below it is furnished with the usual 

 anterior median spine and a minute spinous tubercle between it and the internal 

 median spine. The lower face of the merus is armed with a row of spines along 

 its internal margin and an incomplete row on its external margin made up of 

 about three at the distal end of the joint. 



Length of a cf form I., 93 mm.; length of carapace 49 mm.; length of 

 areola, 17 mm.; width of areola, 4 mm.; length of chela, 67 mm.; width of 

 chela, 262 mm. ; length of dactylus, 45 mm. 



Type locality, Indian Creek, Baileysville, Wyoming Co., W. Va. 

 Two males of the first form, sixteen males of the second form and seven 

 females were collected by Mr. W. P. Hay at this place on the 16th of August, 

 1900. They are in the collection of the U. S. National Museum, Nos. 25,020, 

 28,609, 44,712 (type). 



There are also in the National Museum one male of the second form and 

 two females (No. 28,619) from Crane Creek, W. Va., collected together with 

 C. b. robustus on the 8th of August, 1900, and one male of the first form froni the 

 Elk River, Cogar's Mills, W. Va. 



This peculiar form of C. bartonii resembles C. b. longulus in the form of the 

 rostrum, the wide gape of the fingers of the large claw, and in the absence of a 

 sub-orbital angle. In other respects it is very different from longulus, especially 

 in the shape of the chela which is strongly depressed, with deep longitudinal 

 furrows at the base of the immovable finger, both above and below, as in C. b. 

 robustus, while in C b. longulus the fingers are cylindrical and bearded within 

 at the base. The characteristic gape of the fingers is not present in regenerated 

 claws, which are furnished with very long straight fingers whose cutting edges are 

 straight and meet together throughout their whole length. 



