OF NORTH AMERICA. 357 



narrowing distally, where it is attached to the first accessory albumin- 

 iparous gland. 



Female Organs: Lower portion of oviduct long and narrow; 

 receptaculum seminis very large, short, roundly-pear shaped, its duct 

 large, 5.00 mill, long; first accessory albuminiparous gland very large, 

 ovate. 



The genitalia of danielsi are remarkably uniform. Four measure- 

 ments gave the following results (Dissections No. 23599 and 23623). 



The genitalia do not differ materially from, those of palustris. 

 RANGE: (Figure 42). Indiana. A species of the humid division 

 of the Upper Austral life zone, and of the Upper Mississippi region. 



RECORDS. 



INDIANA: Lake Maxinkuckee, Marshall Co. (Bartsch; Daniels). 



GEOLOGICAL DISTRIBUTION: Unknown. 



ECOLOGY: Probably lives in deep water as usually only dead 

 shells are seen along the shore after storms. (Daniels). 



REMARKS : Danielsi may be known by its acutely pyramidal spire, 

 large body whorl and flaring aperture. It somewhat resembles 

 elongated forms of stagnalis but is smaller. Young forms of palustris 

 somewhat resemble juvenile specimens of danielsi. The shells vary 

 widely in color, some specimens being a rich chestnut brown while 

 others are very light horn colored; nearly all specimens have a dark 

 chocolate aperture, however. The light specimens outnumber the dark 

 ones about two to one. A specimen collected by Mr. Bartsch is cur- 

 iously deformed (pi. XXXVIII, fig. 3) the aperture being entire and 

 separated from the body whorl. 



The series of this species collected by Mr. Daniels is very uni- 

 form, showing that the species is quite stable. The last whorl is more 

 convex and much wider than that of reflexa and the same may be 

 said of palustris from which it also differs in its axis. A few curious 

 variations occur in which the spire is shortened and the aperture is 

 enlarged and expanded. In some specimens the columellar plait is 

 exaggerated to such an extent that it forms a pseudo-tooth. In other 

 specimens the lower part of the aperture is somewhat effuse. A few 

 specimens are strongly scalariform. 



