30 G-eological Survey of Alabama. 



PLEUROTOMA LONGIFORMA, Aldr. PL 2, fig. 10, a. b. 

 P. longiforma, Aldr. J. C. 8. N. H., July, 1885. 



PLEUROTOMA PEREXILIS, n. sp. PL 3, fig. 2. 



Shell slender, acuminate; whorls eight, convex, surface covered by 

 revolving lines, which in some places have finer ones between, especially 

 on the lower half of the shell. Lines of growth faint, very distinct 

 under a glass ; suture bordered below by an impressed line ; slit wide and 

 shallow ; aperture half the length of the shell. 



Locality. Moody's Branch, Jackson, Miss. 



This species is exactly the shape and appearance of Pleuro venusta, 

 Heilprin, but, on submitting the above specimen to Prof. Heilprin, he 

 stated it to be distinct, as P. venusta has its revolving lines arranged in 

 pairs. The type specimen belonged to the National Museum, but on 

 sending our shell there it could not be found, so a comparison could not 

 be made. 



PLEUROTOMA EXILLOIDES, n. sp. PL 3, fig. 9. 



Shell slender; spire high; whorls ten, rounded, slightly shouldered 

 below the suture ; a rather strong impressed line just below, with fainter 

 ones still lower. 



The first four or five whorls of the apex smooth, the others transversely 

 striate, striations very closely set on the body whorl. Slit nearly semi- 

 circular ; outer lip gently curved ; columella bent ; canal short, curved to 

 the right. 



Locality. Lower bed, Wood's Bluff, Ala. 



This species is close to P. perexilis, above described, but differs in the 

 breadth of the body whorl, and the slight shouldering of the same. The 

 slit is larger, and the revolving lines much fainter. 



PLEUROTOMA TOMBIGBEENSIS, n. sp. PL 3, fig. 10. 



Shell large, rather thick and solid, fusiform ; whorls eleven ; suture 

 impressed ; the spire regularly acuminate ; the upper whorls flattened ; 

 lower ones constricted below the suture. 



Body whorl constricted about the center, tapering regularly toward 

 the beak ; a large number of fine sinuous revolving lines upon this lower 

 part. 



Aperture less than half the length of the shell ; slit small, situated at 

 the lower part of the sutural constriction, its outer edge rising up and 



