YIVIPARA. 31 



Paludina lineaia, Valenciennes, Rec. d'Obs. II, 256, 1833. 



I have translated above the original description of Yalenciennes. 

 I have never seen any specimen to which it will apply, but have 

 no doubt such will be found. At present it remains a doubtful 

 species. 



It is referred to Pal. vivipara, of Say, by several authors, but 

 all the specimens of that species which I have seen are not cha- 

 racterized as V. lineata is described as being. (See remarks under 

 V. contectoides.) 



TiTipara troostiana, Lea — Shell ventricose-conical, thin, pellu- 

 cid, yellowish liorn-color, smooth, perforate ; spire short ; sutures very 

 much impressed; whirls four, convex; aperture large, rounded, white. 



Tennessee. Prof. Troost. My cabinet, and cabinet of Prof. Troost. 

 Diam. .68, length .72 inch. 



This is a subglobose species, differing from any which 

 has come under my notice, in having the superior por- Fig. 58. 



lion of the last whirl somewhat flattened, giving the 

 shell a somewhat gibbous appearance. The operculum 

 is rather of a light color, and the plane of the aperture 

 is very refuse at its base. It has a strong resemblance 

 to P. unicolor (Lamarck), and perhaps a stronger one 

 to P. Maheyana (Grateloup). It is more depressed in 

 the spire than either, and the perforation is smaller than Vivipara troosti- 

 in the former, while it is nearly the size of that in the ^^^' 



latter. The aperture is larger than either. Dr. Grateloup has very pro- 

 perly, I think, separated the Malabar species from that which was observed 

 by Olivier in Egypt, and called unicolor by Lamarck. The Egyptian shell 

 has a larger perforation, is darker in color, and is a larger species. I call 

 this after my friend Prof. Troost. {Lea.) 



Paludina troostiana, Lea, Tr. Am. Phil. Soc. IX, 14 (1844). Obs. IV, 

 p. 14. Proc. II, 34 (1841). Arch. f. Nat. 1843, II, 130. 



Paludina haleiana, Lea, 1. c. X, 96, pi. ix, f. 58 (1847). Obs. IV, 70. 

 Proc. IV, 167 (1845). 



I have added to Mr. Lea's description of V. troostiana a view 

 of the type (Fig. 58) in his collection. It will not seem to 

 correspond very exactly with the figure of haleiana, of which 

 a fac-simile is given below (fig. 59). A comparison of all 

 of Mr. Lea's specimens of each has convinced me, however, of 

 their identity. Mr. Lea's description of the latter species here 

 follows. 



