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



EXPLANATION OF ILLUSTRATIONS. 



PLATE I. 



1, Limnaea palustris Miiller. — 2, L. palustris (sufflatus Calkins). — 3, L. 

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

 palustris Mnller variety michiganensis Walker. — 6, L. rejlexa Say. — 7, L. 

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

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

 \&Tiety pinguis Say. — 13, L. columella Say. — 14, L. humilis Say. — 15, L. 

 stagnalis Linn6. 



Issued January 16, 1901. 



