172 CONTRIBUTIONS 



nate ; substance of the shell rather thin ; spire somewhat 

 produced, acute at the apex ; suture small and irregular ; 

 whorls seven, subangular above ; mouth rather narrow ; 

 columella with two folds ; outer lip sharp. 

 Length .9, Breadth .5, of an inch. 



Observations. This is the largest species I have noticed 

 from this deposit. It occurs one half longer than the in- 

 dividual figured. It more strongly resembles the V. spinosa 

 (Lamarck) than any species I know, but differs somewhat 

 in the form, and in not having such strong spines on the 

 superior part of the whorl, these in our species being re- 

 placed by very short spines or compressed tubercles. In 

 some specimens these are disposed to be double, and in 

 others the spines lengthen down the sides and form a kind 

 of rib. A third, very small fold, may sometimes be ob- 

 served in this species above the two large ones. 



V. gradlis. Plate 6. Fig. 180. 



Description. Shell ovately turbinate, transversely striate 

 below, longitudinally and closely ribbed above, coronate ; 

 substance of the shell thin ; spire turrited ; suture linear ; 

 whorls six, angular and canaliculate above ; mouth nar- 

 row, straight ; columella with two folds ; outer lip sharp. 



Length .6, Breadth .3, of an inch. 



Observations. This differs from the Defrancii, in being 

 striate only on the inferior part, and in having close longi- 

 tudinal ribs. The end of the ribs are disposed to be granu- 

 late at the angle. 



