BULINUS. 171 



4. B. BERLANDIERIANUS, W. Q. Bimiey. 



Plate 7. fig. 17. 



Shell cylindrical, smooth, whitened, rather 

 thick ; whorls five, the upper ones narrowly 

 flattened, the lower one comprising more than 

 15—17 of the total length of the shell ; quite 

 compressed ; aperture very long, narrow, colu- 

 mella simple, with a slight callus. 



Length 17, diam. 8 mill. 



Near Matamoras, Texas. 



5. BULINUS TENUISSIMUS, Lea. 



Plate 7, fig. 16. 



Shell subfusiform, exceedingly thin, very 

 fragile, transparent, shining, whitish ; spire 

 produced ; sutures scarcely impressed ; whorls 

 four, slightly convex, the last one very large 

 and somewhat compressed ; aperture large, 

 (.87) 



