18 



LAND AND FRESH-WATER SHELLS OF N. A. [PART II. 



I, 227. — DeKay, N. Y. Moll. 77,excl. syn. cijU»drica,eTT. typ. (1843). 

 —Chemnitz, ed. 2, 22, pi. iii, f. 20-22. 

 Physa hildrethiami, Lea, Pr. Am. Phil. Soc. II, 32 (1841) ; Trans. IX, 7 

 (1844) ; Obs. IV, 7. 



It is mentioned in catalogues, &e., as inhabiting a wide area, 

 the extreme points being Vermont, San Francisco, Michigan, 

 Georgia, Louisiana and Utah. 



Mr. Say's typeof P/i^sa gyrina is still preserved in the Academy 

 at Philadelphia. It is drawn in Fig. 130. 



No. 8108 of the collection was labelled Ph. elliptica, by ]Mr. 

 Lea. It does not appear to me distinct from this species, in the 

 synonymy of which it is also placed by Haldeman. A copy of 

 Lea's original description and figure here follow. The name has 

 also been used by Parreyss. 



Phijsa elliptica, Lea. — Shell sinister elliptical, very thin, pellncid, chest- 

 nut colored, shining; spire rather short; whirls four; outei 

 Fig. 131. lip margined ; aperture narrow. Diam. .2, length .5 inch. 



Hab. : T. G. Lea. My cabinet. 



This species is less inflated and more of a chestnut color than 

 any I am acquainted with. Its color is almost reddish, and the 

 light-colored margin of the outer lip is remarkable. The aper- 

 ture is rather contracted, and the whole shell somewhat elon- 

 gate. (Lea.) 



Phj/sa 

 tlliptica. 



Fig. 132. 



Physa Mldrethiatia, Lea, also appears to me a synonym of 

 Phym gyrina. Mr. Lea's description and a figure of his original 

 specimen here follow. 



Physa hildrethiann, Lea. — Shell elliptical, somewhat compressed, long, 

 somewhat pellucid ; spire obtusely elevated ; whirls five ; 

 lip margined ; ai)erture long, compressed. 



Hab. A lake in Illinois : Dr. Hildreth. Diam. .40, length 

 .75 of an inch. 



This species is among the largest, and is perhaps the most 

 remarkable Phi/sa yet observed in this country. The aper- 

 ture is little more than half the length of the shell. The 

 apex is very obtuse, and the whole shell is somewhat cylin- 

 drical. A single specimen was brought by Mr. Nicklin from 

 Dr. Hildreth, and I name it after him, as he seems first to 

 have observed it. (Lta.) 



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