GASTEROPODA OF THE LOWER GEEEN MARLS. 83 



Genus VASUM Bolton. 



Vasum conoides, n. sp. 



Plate IX, Figs. 9, 10. 



Shell rather small, regularly couoidal above and below the point of 

 greatest diameter, which is at the upper edge of the body volution ; spire 

 longer than the shell below, as seen from the back of the volution; and 

 very evenly and gradually diminishing ; number of volutions unknown but 

 apparently numerous; apical angle about 35°; aperture elongate, nar- 

 row, becoming pointed below, the length as given by projecting the spire 

 of the shell to an imaginary apex is rather less than one-third as long as 

 the entire length of the shell; columella moderately strong, marked by 

 three proportionally strong folds and indications of a smaller fourth one 

 very near the base; surface of the cast perfectly smooth with the excep- 

 tion of a broad sulcvis marking its surface on the last volution, at about 

 one-third of the distance below the upper edge, indicating either a thick- 

 ening of the inside of the shell or a sinuosity in the outer lip. 



Of course there is no indication on the internal cast of the outside 

 markings of the shell, but the spire, as shown by the volutions, has been 

 very much elevated, and nearly twice as high as the last volution on the 

 front or apertiu'e side of the shell, in which respect the shell would have 

 differed from the living forms of the genus Vasum. The cast shows that 

 the upper folds of the columella were much stronger than those below, 

 which, when taken in connection with the elevated spire, would lead one 

 to believe it to be related to some forms of Mitra, but the abruptly terminat- 

 ing upper surface of the volutions indicates a form of suture incompatible 

 with any of the Mifras, which do not possess a longitudinally jjlicated sur- 

 face of a character such as would be transmitted to the cast; it also indicates 

 a thickness of shell unlike any of those. Considering all these evidences, 

 I have concluded that, without the exterior of the shell to aid me, I should 

 be much safer in referring the species to the TurbinelUdce than to the MitrkJa. 

 It also bears considerable resemblance to casts of high spired species of 

 Strombus, but the plications on the collumella remove it from that group, 



