AM NICOLA. 



SI 



Aiuiiicola parva, Lea.— Shell obtusely coniccal, rather thin, yel- 

 lowish, smooth, umbilicate ; spire short ; suture impressed ; whirls four, 

 inflated ; aperture large, nearly round. 



Springfield, Ohio. Diam. .15, length .18 inch. Fig. 171. 



The shell described by Mr. Anthony as Paludina cincin- 

 natiensis, resembles this species, but is more elevated in the 

 spire, and is a larger shell. It is more nearly allied to Amni- 

 cola orhiculata, herein described, but may be distinguished by 

 its being a smaller shell, and being less round in tlie aperture. 

 The base of the lip is disposed to be slightly angular ; the 

 aperture is about one half the length of the shell. {Lea.') 



Aiimicola pnrra, Lea, Tr. Am. Phil. Soc. IX, 16 (1844); Obs. IV, 16; 

 Proc. II, 34 (1841).— Haldeman, Mon. p. 24 (1844?). 



Figure 151 is drawn from Mr. Lea's original specimen. 



Amnicola orlJiculata, Lea. — Shell orbicular, rather thin, yellow- 

 ish, smooth, umbilicate ; spire short ; sutures much impressed ; whirls 

 five, inflated ; aperture large, round. 



Springfield, Ohio. Schuylkill ? near Philadelphia. Diam. Fig. 172. 

 .18, leugtli .18 inch. 



This species is very nearly allied to Am. parva, and may 

 prove to be only a variety of it. The specimens before me 

 are all larger, and they appear to be more globose. The 

 aperture is about half the length of the shell. I found a 

 single specimen of this species among many small shells 

 which were thrown together in a box, as being collected from our vicinity. 

 It may be possible it is an Ohio specimen gotten by mistake into the box. 

 Found also in Cayuga Lake. (Lea.) 



Amnicola orhiculata, Lea, Tr. Am. Phil. Soc. IX, 16 (1844) ; Obs. IV, 16 ; 

 Proc. II, 34 (1841).— Haldeman, Mon. p. 24 (1844?). 



Figure 153 is drawn from Mr. Lea's original specimen. 



Fig. 173. 



Amnicola lon^iiiqiia, 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. f/alhuna, or like miniature speci- 

 mens of Paludina ponderosa. It has a bleached 

 or chalky color, probably from exposure, like the Amnieola longinqua. 



