Synopsis Fresh-Water Moli^usca 



Fig. 2 

 Type: L. sf agnails L,. 



Example: L. sfagnalis appressa Say, fig. i. Radula, fig. 2, 



Subgenus PSEUDOSUCCINEA Baker, 1908. 



Shell thin, succineif orm ; spire short ; body-whorl large, 

 elongated, not inflated; surface sculptured with spiral, incised 

 lines ; axis gyrate. .,^ags>^ 



"Prostate long, narrowly cylindrical with a slight ^^^^ 

 bulbous termination ; penis thick, about half as long Wf 



as penis-sac; lateral teeth bicuspid." 1- 



Fig. 4 

 Type: L. columella Say, fig. 3. Radula, fig. 4. Jaw, fig. 5. 



Fig. 6 



Subgenus RADIX Montfort, 1810. 



Shell thin, globose-oval ; spire short, acute ; body- 

 whorl large, inflated ; aperture very large ; lip ex- 

 panded. 



"Prostate short, pear-shaped when viewed lateral- 

 ly ; penis very slender, longer than penis-sac ; first lat- 

 eral tooth tricuspid, balance bicuspid." 



. Fig- 7 

 Type: L. aiiricularia h., fig. 6. Radula, fig. 7, 



