24 Trans. Acad. Sci. of St. Louis. 



EXPLANATION OF ILLUSTRATIONS. 



PLATE I. 



1, Limnaea palustris Muller. — 2, L. palustris (sufllatus Calkins). — S } L. 

 reflexa Say, elongate form. — 4, L. reflexa variety attenuata Say. — 5, L. 

 palustris Miiller variety michiganensis Walker. — 6, L. reflexa Say. — 7, L. 

 reflexa variety scalaris Walker. — 8, L. desidiosa Say. — 9, L. catascopium 

 Say. — 10, L. cubensis Pfeiffer. — 11, L. caperata Say. — 12, L. catascopium 

 variety pinguis Say. — 13, L. columella Say. — 14, L. humilis Say. — 15 ; L. 

 atagnalis Linn6. 



Issued January 16, 1901. 



