LYMN^EUXE OF NORTH AMERICA. 231 



seminis small, rounded, its duct one-fourth longer than the penis-sac; 

 vagina rather long. 



The comparative measurements may be tabulated as follows i 1 



Prost. Penis-isac 



Penis. Penis-sac. Vas. def. duct. Rec. sem. Penis retr. retr. Shell. 



2.00 3.00 7.00 5.00 4.00 2.00 1.50 14.90 



2.00 3.00 7.00 6.00 4.00 2.00 1.50 13.00 



2.00 3.00 7.00 6.00 4.00 3.00 2.00 14.00 



There is very little variation in the genitalia of caperata, the size 

 and shape of the different organs being quite uniform. 



RANGE (Figure 19) : From Quebec and Massachusetts west to 

 California; Yukon Territory and James Bay south to Maryland, In- 

 diana, Colorado and California. 



Caperata is a species of northern distribution, occupying portions 

 of the Canadian, Hudsonian, Mackenzian, Yukonian, Columbian, 

 Coloradoan, Californian, Great Basin, Upper Mississippian and Nova 

 Scotian regions. Its center of distribution embraces a broad belt across 

 the center of North America from about the 38th to the 52nd degree 

 of north latitude, the belt being, therefore, about fourteen degrees in 

 width. Caperata is a characteristic species of the Upper Mississippi 

 Valley, from whence it has migrated to other parts of the country. 

 So far as the forests are concerned, it seems to extend only slightly 

 into the deciduous area in the southeastern part of its range, but occu- 

 pies a large part of the coniferous area, as well as of the plain and 

 prairie areas. 2 It extends through the Hudsonian, Canadian and Tran- 

 sition life zones. 



The range of caperata has been restricted by some conchologists 

 to the country east of the Rocky Mountains, but the records from 

 California, Utah and Washington are authentic and there is no doubt 

 of the range of this species to the Pacific Coast. Further records are 

 needed from the western states and especially from British America, 

 where the records indicate a northwesterly range to Alaska. 



iDissection No. 23907. : Dissection made in July, from Joliet, Illinois, 

 specimens. 



2 There are several records of this species from Louisiana and Texas, but 

 no specimens have been seen from any state south of Indiana and Colorado; 

 these records are believed to have been founded on some forms of the cubensis 

 group, possibly Galba bulimoides techella or Galba cubensis, both of which 

 bear some resemblance to caperata. The references and localities are as 

 follows: 



Adams, Sh. Red Riv. Louis., p. 244. 1854. 



Sing-ley, An. Rep. Geol. Surv. Texas., IV, p. 188, 1892; p. 313, 1893. 



Frierson, Nautilus, XIV, p. 68, 1900. 



The first locality is near Cache Creek, Oklahoma; the Texas localities are 

 in Hardeman, Gillespin, Baylor, Reeves. Swisher, Cottle and Stonewall coun- 

 ties; Frierson records a small species from the great raft in the Red River, 

 doubtfully as caperata. The writer has not been able to secure specimens from 

 these localities for the verification of the records. Call's records from Cimarron 

 River, Oklahoma, and from Elk Creek, Barber County. Kansas, need confirma- 

 tion. We suspect these to have been based on a variety of bulimoides. 



