602 



PROCEEDINGS OF THE ACADEMY OF 



[Nov., 



A NEW SPECIES OF CLAVILITHES FROM THE EOCENE OF TEXAS. 



BY C. W. JOHNSON AND A. W. GEABAU. 



Clavilithes chamberlami n. sp. 



The spire of this species is long and slender, as in C. henne- 

 dyanus Harr., with which the early whorls of the shell agree 

 pretty well. Only a portion of the protoconch has been observed, 

 but it is apparently of the same character as that of the American 

 species of this genus generally, unless more slender than the 

 normal. The spire contains about seven ribbed whorls; the suture 

 is moderately depressed ; the ribs are swollen near the middle, but 



become obsolete toward the suture; they are at first more than their 

 width apart, but later become broader and the interspaces corre- 

 spondingly narrower. A subsutural band occurs, and is quite 

 strongly marked on the later ribbed whorls, indicating a pro- 

 nounced posterior canal at this stage. 



Spirals on the first five whorls, single, coarser in the centre, but 

 becoming finer toward the sutures; interspiral spaces broader than 

 the spirals. Intercalation of secondary spirals begins on the sixth 

 whorl. On the seventh whorl the ribs become broad and ill 



