PLEUROCERA. 



67 



Fig. 1-29. 



Observations. — This is the largest species of Trypanostoma of <jur 

 country Avhich I have seen. It is nearly two inches 

 long and is athletic. It is closely allied to Melania 

 ( Trypanostoma) canaliciilata and undidata, Say, which 

 two may indeed be only varieties of each other. It 

 has a carina like each of them, and this is sometimes 

 slightly nodulous lilce the latter, and there is a slight 

 furrow-like impression above the carina which 

 reminds one of the former. The whorls are remark- 

 ably flat and the color of the epidermis is more 

 brownish. Three specimens out of six before me are 

 more or less banded inside. The specimen from 

 Tuscumbia is whitish inside and has two indistinct 

 bauds. It is an imperfect specimen, and may really 

 not belong to this species. The aperture is more than one-fourtli the 

 length of the shelL — Lea. 



Fig. 130, 



Fig. 131, 



11. P. Troostii, Lea. 



Trypanostoma Troostii, Lea, Proc. Acad. Nat. Sci., p. 171, 1862. Jour. Acad. Xat. 



Sci., V, pt. 3, p. 285, t, 36, f. 107. Obs., ix, p. 107. 

 Trypanostoma viride. Lea, Proc Acad. Nat. Sci., p. 172, 1862. Jour. Acad. Xat. 



Sci., v,pt. 3, p. 291. t.36, f. 119. Obs., ix, p. 113. 

 Trypanostoma iigatum. Lea, Proc. Acad. Nat. Sci., p. 171, 1802. J^our. Acad. Nat. 



Sci., V, pt. 3, p. 288, t. 36, f. lU. Obs., ix, p. 110. 



Description. — Shell carinate, conical, very much inflated, yellowish 

 horn-color or greenish, banded or Avithout bands ; sutures irregularly 

 and very much impressed ; Avhorls about nine, rather impressed, some- 

 times cliannelled ; aperture large, rhora- 

 boidal, whitish and sometimes banded 

 within; outer lip acute, sinuous, columella 

 thickened below anU very much twisted. 



JJahitat. — Tennessee; Prof. G. Troost : 

 Florence, Alabama; Rev. G.White: Oos- 

 tenaula River, Georgia; Bishop Elliot: Fox 

 River, near New Harmony, Indiana; J. 

 Sampson. 



Diameter, -04; length, 1-21) inclies. 

 Observations. — I have five specimens before me; that from the late 

 Prof. Troost (after whom I have great pleasure in naming it), I liave 



