ANNELID GENUS CAMBARINCOLA — HOFFMAN 



327 



Figure 31. — Distribution of the two species of the Vitrea group. 0> Camharincola vitrea; 

 #, C. osceola. Symbols represent the localities from which specimens have been 

 examined; no literature records included. 



Distribution. — On the basis solely of material personally ex- 

 amined, vitrea is found to be widely distributed in the upper Mississippi 

 Valley and Great Lakes region, and various published records (some 

 doubtless incorrect) extend the range even more broadly. As 

 presently known, the range of vitrea extends from the Red River in 

 Arkansas north to the Great Lakes, and from Michigan and Illinois 

 west to the foothills of the Rockies. 



Presumably the species may be found in Indiana, but it was not 

 represented in any of the collections made by Dr. Holt in a north- 

 south traverse of that State in 1958. It may be found that the 

 population of northern Michigan arrived by crayfish from the west 

 across the Straits of Mackinac during the postglacial occupation of 

 Wisconsin. 



Future collectors will have plenty to do in rounding out our knowl- 

 edge of the distribution of this easUy recognized species. Existing 

 confirmed records are tliose of the following collections: 



Colorado: boulder county: St. Vrain's Creek near Boulder, May 1915, Max 

 M. Ellis (USNM 17670, 4 slides), tuma county: Arikaree River near Beecher's 

 Island, October 1915, B. Jaffa (USNM 17677, 2 slides). 



