43 6 MEMOIRS OF THE CARNEGIE MUSEUM 
in the formerly glaciated area, for these are due to Postglacial expansion. But 
looking upon the Jocalities south of the terminal moraine (Pl. XLII, Fig. 3) we see 
that only a few are known for C. propinquus, and these are all in southern Indiana 
(Brown, Monroe, and Green Counties), and belong very likely to the old Lower 
Ohio drainage, but in the region where it comes into contact with the supposed Old 
Miami River (or possibly some other river flowing north in the State of Indiana). 
Since we have reason to believe (Ortmann, 1905), p. 114) that the center of radia- 
tion of the subgenus Fuxonius, to which the propinquus-group belongs, is in the 
central basin formed by the three great rivers (Missouri, Mississippi, and Ohio), C. 
propinquus distinctly points toward this center, of which southern Indiana forms 
part. This is the more interesting since we see that it is the most primitive species 
of the propinquus-group which most closely approaches the original center. In 
Preglacial times C. propinquus belonged to the northeastern extremity of the old 
Ohio drainage (Lower Ohio), and in this region there apparently was a chance for 
it to cross over the continental divide into the Atlantic (St. Lawrence) drainage. 
If, however, the Erigan River drained to the Mississippi, the presence of this 
species in the Lower Ohio and in the lower part of the Erigan River is more easily 
accounted for by direct communication of the waters. 
Taking up the distribution of C. propinquus sanborni, we observe that until 
recently only one locality was known to the south of the drift, namely, the type 
locality in Carter County, Kentucky, which is undoubtedly in the drainage of the 
Old Kanawha River. In addition, I have discovered a number of localities in 
eastern Ohio (Carroll, Harrison, and Stark Counties), and in northern West Virginia, 
which belong to the same drainage (Newark River and Marietta River, tributaries 
of the Old Kanawha), which are also outside of the glaciated area (at Canton, 
Stark County, Ohio, close to the edge of the drift). 
The chorological facts about the distribution of C. propinquus and C. propinquus 
sanborni are very meager, and not at all satisfactory; but as far as our present 
knowledge goes, all known localities of C. propinquus sanborni, outside of the drift, 
are in the drainage of the Old Kanawha, while none of the known localities of C. 
propinquus are in this drainage, but are situated to the west of it. Now, this 
mutual relation between distribution and Preglacial drainage becomes more evident 
when we look upon C. obscwrus, the distribution of which I have studied more 
closely. 
“They are close to the southern edge of the drift, and it is a little doubtful whether they are inside or outside of 
it. Disregarding the Illinoisan drift, they are surely outside of the Postillinoisan glaciation, as is also a locality in 
Franklin County, Ind. 
