4 AMNICOLA. 



prominent, situated at the external or posterior base of the tentacula ; 

 base or foot of the animal dilated, oval, obtuse before and behind. 



Found under stones, &c., in moist situations, on the margins of rivers. 

 Like those of the genera Lymncea and Planorhis, this animal possesses the 

 faculty of crawling on the surface of the water, in a reversed position, the 

 shell downward. {Say.) 



Cyclostoma lajndaria, Say, Journ. A. N. S. Phila. I, 13 ; Binney's ed. 59. 

 Amnicola lapidaria, Haldeman, Mon. p. 18, pi. 1, f. 10. 

 Paludina lapidaria, KijsTER in Chemn., ed. 2, p. 54, pi. x, f. 21, 22. 

 Melania lapidaria, Lewis, Bost. Proc. VIII, 255. 



This is a widely distributed species, ranging at least from 

 Georgia to New York, and from Missouri to Michigan. It is 

 also found in the postpleioceue of the Mississippi River bluffs. 



In its habits it differs from most Amnicolae, being often far 

 removed from water, in positions favorable to strictly land spe- 

 cies. This fact, of course, would not necessitate its removal from 

 the genus, as such instances have been noticed in other genera. 

 The anatomist must decide the question of its generic station. 



Amnicola longinqua, Gould — Shell small, elongate-ovate, 

 smooth; apex obtuse ; whirls 5, rounded ; suture deep ; aperture elliptical, 

 rounded posteriorly ; columella very arcuate, sub-perforate. Length one- 

 eighth, breadth, one-tenth inch. 



Found in the Colorado Desert (Cienaga Grande) by W. P. Blake. 



In form it is much like A. cincinnatiensis, Hald., or like A. galbana, or 

 like miniature specimens of Paludina ponderosa. It has a bleached or 

 chalky color, probably from exposure, like the other species found on the 

 Cienaga Grande, a region which is immersed a portion of the time, and 

 dry the remainder, and was once, apparently, an extensive marsh, or 

 shallow lake. (Gotdd.) 



Amnicola lonrjinqua, Godld, Pr. Bost. S. N. H. v, 130. 



Amnicola uickliniana, Lea — Shell turreted, green, smooth ; 

 apex obtuse ; whirls 4, convex ; aperture 

 Fig. 5. ovate. Hot Springs, Va. Diam. two- pig. g, 



twentieths ; length three-twentieths inch. 



This shell, with several other species, ^) 



was brought by Mr. Nicklin from the Hot C/\ 



Springs of Virginia, and kindly placed ^^ 



in my cabinet. It lives in a rivulet, Amnicola 

 Paludina ^jjogg channel is supplied by the waters ''^iMiniana. 



of a hot and a cold spring. The Physa 

 aurea inhabits the same stream. It is the smallest species I know in our 

 country, except the granosa of Say. It is rather larger, and very much re- 



