GASTEROPODA OF THE LOWER GREEN MARLS. 69 
NOTES ON THE GENUS PIESTOCHILUS MEEK AND VOLUTOMORPHA GABB. 
In the report of the U.S. Geol. Surv. of the Terr., Vol. 1x, Invert. Pal., 
p. 356, Mr. Meek describes the genus Piestochilus as a division of the 
Fasciolariide. His description is as follows: 
Shells of small size, with spire and canal produced; volutions flattened or 
moderately convex and finally spirally striated, sometimes with vertical folds; 
plait or plaits of columella not exposed in a direct view into the aperture, very 
oblique, and occupying a higher position than in either of the foregoing, [ Fascio- 
laria Lamarck and Terebrispira Conrad] outer lip smooth within. 
As the type he gives Fusus Scarboroughi M. & H. This shell is a 
medium sized, rather slender, fusiform species, almost equally long above 
and below the point of greatest diameter, which is at the swell of the body 
volution; the canal is rather short and straight, and the columella is provided 
with two distinct, although small, very oblique folds. In examining the 
shell few persons would fail to recognize at once its very close relations to 
Fasciolaria Lamark, especially to such species as those forming the group 
containing Lamark’s type, F: tulipa; the principal differences being in the 
more slender form and comparatively straight canal, which is not so abruptly 
contracted at the base of the outer volution. They also somewhat resemble 
a group of Mitras, such as M. scrobicularia Broochi, and more distantly M. 
granatina Lam., a living species, though. differing in the form of the aper- 
ture and in the character of the columellar folds. 
During the year in which the above-named work was published 
(1867), Mr. W. M. Gabb deseribed and published? his genus Volutomorpha, 
founding it upon Volutilithes Conradii Gabb, described and figured in the 
Jour. Acad. Nat. Sci., Phila. 2d ser., vol. 4, p. 300, PI. xvii, Fig. 10. 
This genus as typified by that species is quite distinct generically from 
Piestochilus. The generic description originally given is: 
Shell elongate, fusiform ; whorls cancellated by longitudinal and revolving 
ribs ; columella with one very oblique fold, and sometimes one or more smaller 
secondary folds. In shape this genus is not unlike the two preceding genera [ Vol- 
utoderma Gabb, and Fulgoraria Schum], but it differs from them all in having 
essentially a single large oblique fold. When more than one occurs, the secondary 
folds are smaller than the large primary. 
1Proc. Acad. Nat. Sci., Phila., 1876, p. 290. 
