868 iMRMOlKS OF THE CARNEGIE MUSEUM 



the fii'st form collec-ted in Fishing CJreek, West Virginia, only two liad no trace of 

 it; six had a curve developed in its place, and in five others it was distinct, in one 

 or two representing a blunt angle. The length of the tips of this organ vai'ies 

 sliglitly, but it is generally less than in C. uhscinKs. The tip of the inner part 

 always corresponds to that of the Oberlin specimens, Iteing compressed and rounded 

 off. 



6. The annulus of the female is always of the propiiiqnus-typL', that is to say, 

 flat, with no tubercles. In old females it liecomes a little uneven, the anterior and 

 posterioi- parts being slightly swollen, but tliere are never two distinct tuljercles as 

 is the case in ('. ohscii.rns. 



We may condense the varietal characters of this form as follows: 



C. projiiv(ji(iis sanhanii clearly is nearer to proplnqmts than to C. ohscurufi on 

 account of tlie lack of a distinct shonldei' on the anterior margin of the copulatory 

 organs of the male of the tirst form, on account of the general shape and size of this 

 organ, and further, on account of the flat female anm/lus. It diftei's from ('. pro- 

 pincpms in the flattened and rounded tiji of the irnier part of the male oi-gan, in the 

 lack of a median keel on the rostrum, and in the shaj)e and ai'mature of the cheli- 

 peds, although the latter diflerences are slight and not always reliable. Just in the 

 latter characters, and in the tendency to develop a notch on the anterior margin of 

 the male organ, it inclines toward ('. obscurus. Thus it is clearly a transitional 

 form toward ('. uhsciirus of western Pennsylvania, and its geographical distribution, 

 as we shall see below, is also intermediate between ('. prcqnnquus and ('. ohscurus. 



The colors of C. sanhonu agree throughout with those of (*. propiuquus and 

 (J. obscurus. The color of the newly laid eggs is dark olive-green, sometimes almost 

 black. 



There are one hundred and sixteen specimens of this variety at hand ; Ave are 

 from the Lake Erie drainage in noi'thern Ohio ; eiglity-one from the Tuscarawas 

 drainage in eastern Ohio, and thirty from Fishing and Middle Island Creeks in West 

 Virginia. 



DISTRIBUTION. 



(See Plate XLII, Fig. 3.) 

 LOCALITIES RErRESENTED IN THE CARNEGIE MUSEUM. 



Ohio: Lorain Countii, Waterworks Reservoii', Oljerlin (R. L. Baird coll., exch. 

 Mus. Oberlin); Stark ('ok id;/, West Ih'anch of Nimishillen Creek, Canton; Carroll 

 CounJij, (Jonotton Creek, New Hagerstown ; Harrison, ('oiotfi/, (Jonotton Creek, 

 Bowerstown; Tascarairas Couiiti/, Deimison [V. Sterki coll.). 



