PJ.ANORBIS. 



12'7 



Fig. 211. 



Planorhls hrogniartlana, Lea, Tr. Am. Phil. Soc. IX, 24 ; Obs. IV, 24 



(1844) ; Pr. II, 242 (1842). 

 PJanorbis lentlcularis, Lea, Tr. Ain. Pliil. Soc. IX, 6; Obs. IV, 6 (1844). 

 Planorhis buchaiiensis, Lea, Tr. Am. Phil. Soc. IX, 6 (1844) ; Pr. II, 32 



(1841) ; Obs. IV, 6. , 



Paludina hyaJina, Lea, Tr. Am. Phil. Soc. VI, 17, pi. xxiii, f. 81 ; Obs. 



II, 17 (1839). 



The species has been quoted from New Englaud to Kansas and 

 the District of Columbia. 



The single individual from which Mr. Lea drew his description 

 of Paludina lujalina has been lost. I have not seen it. The 

 following copy of the original description and figure will at once 

 convince the reader of its being a distorted specimen of Planorhis 

 exacutus. 



Paludina hyalina, Lea. — Shell obtusely conical, carinate, diaphanous, 

 flattened below ; whirls four ; sutures very much impressed ; aperture 

 widely rounded. Diam. .2, length .2 inch nearly. 



Near Poland, Ohio : Dr. Kirtland. Cabinet of Mr. Hyde. 



Dr. Kirtland sent the only specimen of this shell I have 

 seen to Mr. Hyde, under the impression that it was a de- 

 formed specimen of Planorhis. Mr. Hyde communicated 

 it to me as a new species, of which there cannot, I think, 

 be a doubt. It is very remarkable for the flatness of the 

 inferior portion of the last wliirl, and for the carina on 

 the periphery which this causes. It is perhaps thinner 

 and more transparent than any species yet described. (Lea.) 



Planorhis huchanensis, Lea, is evidently synonymous with P. 

 exacutus. The original description and figures from Mr. Lea's 

 type now follow : — 



Planorhis buchinensis, Lea. — Shell sub-lenticular, above sub-convex, 

 carinate at the periphery, beneath narrow umbilicate, horn- 

 color or brownish, smooth ; whirls three ■ lip sharp ; aperture 

 rounded. 



Hub. Near Cincinnati, Ohio: R. Buchanan. My cabinet, and 

 cabinets of T. G. Lea and R. Buchanan. Diam. .12, length 

 .08 of an inch. 



Several specimens of this species were sent to me several 

 years since by my brother T. CI. Lea, who informed me that 

 they were first observed by Mr. Buchanan, after whom I name 

 it. This species is very nearly allied to P. lens, Nobis, but it 

 may at once be distinguished by its round aperture, which is 

 somewhat spread out. The aperture of the le/is (now lenticuluris), is iri- 

 angular, and the size of the shell rather larger. {Lea.) 



Fig. 212. 



@> 



Planorhis 



hucha- 

 nensis. 



