132 



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



Fig. 246. 



Observations.— Among the moUusca brought long since by my friend, 

 the late Prof. Vauuxem, were about a dozen of this little species. 

 The district of the State was not given with the habitat. In 

 some of the specimens there is a disposition to put on a pur- 

 plish mark on the inside of the base of the columella. In 

 most of the specimens there is a pale light line immediately 

 below the suture. This species is allied to simplex, herein 

 described, but may be distinguished by its being more slen- 

 der, being a darker horn-color, and in having a more elongated aper- 

 ture. The aperture is about one-third the length of the shell.— iea. 



Figured from Mr. Lea's plate. 



78. P. curvatum, Lea. 



Melania curvata, Lea, Philos. Proc. ii, p. 243. Philos. Trans, ix, p. 28. Obs. ix, 

 p. 28. VVheatley, Cat. Shells.U. S., p.25. Brot, List, p. 30. Binnet, Check 

 List, No. 81. 



Gyrotoma curvata, Say, ? Adams, Genera, i, p. 305. 



Fig. 247. 



Description. — Shell obtusely carinate, somewhat pyramidal, rather 

 thick, dark horn-color ; spire somewhat elevated ; sutures 

 impressed; whorls eight, convex; aperture small, curved, 

 whitish. 



£a6iY«f.— Tennessee. 



Diameter, -40 ; length, -73 inch. 



Observations. — The two specimens before me vary very 

 little in all their characters. This is a very distinct species, 

 resembling more, perhaps, M. conica, Say, than any other. 

 The whorls are close, and about the middle are placed two 

 or three obscure cariuse, which cause a slightly impressed channel. 

 The aperture is small, being a little moi'e than one-third the length of 

 the shell. The outer lip is sharp and very much curved, causing the 

 base of the columella to be twisted. In one of the specimens an 

 obscure band near the base in the interior may be observed. — Lea. 



77. P. simplex, Lea. 



Trypanostoma simplex, Lea, Proc. Acad. Nat. Sci., p. 174, 1862. Jour. Acad. Nat. 

 Sci., V, pt. 3, p. 277, t. 36, f. 94. Obs. ix, p. 99. 



Description.— ^haW smooth, conical, rather thick, yellowish-olive; 

 spire rather elevattd; sutures somewhat impressed; whorls eight, 



