Notes on TertitDy Fossils zvith Descriptions of Nezv Species. 83 



SiGARETUS (SiGATICUS) CLARKEANUS, 11. Sp. 



Shell rather thick, rotund, whorls five, suture linear, surface of 

 body whorl with a large number of impressed lines almost obsolete 

 in the centre but numerous and distinct above and below ; umbili- 

 cus striate within; aperture lunate, inner lip covered with a callus, 

 thickening towards the posterior part. 



Locality: Choctaw Corner and Hatchetigbee Bluff, Ala. 



This peculiar shell posesses the form of Natica, but the lines 

 of Sigaretiis. It constitutes a second species of the subgenus. 



Physa choctavensis, n. sp. 



Shell thin, minute, rather obtuse and broad, whorls probably 

 five, somewhat shouldered, outer lip slightly patulous, inner lip 

 reflected and reaching well upon the body wall, surface showing 

 lines of growth only. 



Locality: Choctaw Corner, Ala., Woods Bluff Group. 



Resembles somewhat very young specimens of the com- 

 mon P/irsa hderostropJia, Say, but presenting differences 

 enough to constitute a distinct Species. 



Five specimens found. 



Physa elongatoidea, n. sp. 

 • Shell thin, minute, strongly sinistral, whorls five, smooth, su- 

 ture strongly impressed and very oblique to the axis, aperture 

 almost quadrate, inner lip meeting the parietal wall abruptly and 

 reaching down nearly straight . 



Locality same as previous species. 



This form is peculiar in departing from the American living 

 types and being more elongate than any here known. It might be 

 mistaken for a species of Limnea if it was not sinistral. The only 

 specimen found is a young shell. 



Mathilda claibornensis, n. sp. 



Shell very minute, embryonic whorls three^ and placed as usual 

 in the genus, the adult whoris, (but three remaining in the type) 

 with three rounded smooth ring like bands, the intervening spaces 

 having impressed longitudinal lines which do not pass over the 

 bands. 



Locality: Claiborne Ferruginous Sand. 



Very rare, but the second species known from this famous 

 deposit. 



