GASTEROPODA OF THE LOWER GREEN MARLS. 83 
Genus VASUM Bolton. 
VASUM CONOIDES, h. Sp. 
Plate rx, Figs. 9, 10. 
Shell rather small, regularly conoidal 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, lar- 
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 pertectly smooth with the excep- 
tion of a broad sulcus 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 aperture side of the shell, in which respect the shell would have 
differed from the living forms of the genus Vaswum. 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 Mitras, which do not possess a longitudinally plicated 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 Zurbinellide than to the Mitride. 
It also bears considerable resemblance to casts of igh spired species of 
Strombus, but the plications on the collumella remove it from that group, 
