LYMN^EID.E OF NORTH AMERICA. 337 



The above figures show that the organs are somewhat variable in 

 form. Some of the variation, however, is due to the contracted con- 

 dition of the alcoholic specimens. In one individual, the receptaculum 

 seminis was rounded instead of quadrangular (pi. XII, fig. Ej, but 

 in all other specimens it was as in figure A. 



In the immature form (called crystalcnsis) the retractors of the 

 male organs vary considerably. (PI. XV, fig. A.) One specimen (1) 

 had the penis retractor attached to the penis-sac retractor; a second 

 penis-sac retractor was present, its insertion in the columellar muscle 

 being some distance from that of the posterior retractor. The posterior 

 protractors also varied in position and number in one specimen (2), 

 having their insertions in the columellar muscle, very close together. 

 Three measurements of the immature individuals are given below : 



Penis. 



Penis-sac. 



Penis 

 ret. 



Penis-sac 

 ret. 



Vas. def. 



Prost. 

 duct. 



Ret. sem. 

 duct. 



Shell. 



3.50 



4.00 



2.00 



1.50 



11.00 



5.00 



4.00 



21.00 



3.00 



4.00 



2.00 



1.75 



13.00 



5.00 



4.50 



21.00 



3.00 



4.00 



2.00 



1.25 



16.00 



6.00 



6.50 



27.00 



An egg capsule, deposited in the pond of the zoological laboratory 

 of the University of Chicago, measured 34.50 by 1.60 mill, and con- 

 tained 130 eggs. 



The chief characteristic of the genitalia of reflexa is the form of 

 the receptaculum seminis ; otherwise they do not differ markedly from 

 those of palustris. 



Range (Figure 37) : Eastern Quebec (65°) to Nebraska (100°) ; 

 Manitoba (50°) south to southern Illinois and southern Kansas (37°). 



Reflexa is characteristic of the humid divisions of the Transition 

 and Upper Austral life zones, extending northward into the Boreal 

 (Canadian) life zone. It is not authentically known west of the 100th 

 meridian, nor does it enter the Lower Austral, the 37th parallel mark- 

 ing its southern limit. Compared with the regional map, reflexa is 

 seen to range through the Canadian and a large part of the Upper 

 Mississippian regions, embracing the drainage areas of the Great Lakes, 

 of the St. Lawrence River and of the upper portions of the Mississippi 

 River. It reaches its greatest development in the prairie region of 

 the central west. References to this species from localities west of 

 the 100th meridian have all proved to be Galba proximo, and var. 

 rozvelli, which the immature reflexa greatly resembles. Binney (p. 41, 

 Cat. Nos. 3523 and 8734) has confused the species with rozvelli. Tay- 

 lor's reference of this species to Red Deer, Alberta,, was probably 

 founded on narrow forms of palustris. 



