TO GEOLOGY. 131 
casts. Three species are described by Say and Conrad 
from the Miocene of Maryland. 
FAMILY CANALIFERA. 
GENUS CERITHIUM? Bruguiere. 
C. striatum. Plate 4. Fig. 122. 
Description. Shell turrited, transversely and finely stri- 
ate ; substance of the shell rather thin ; apex acute ; suture 
not deeply impressed; whorls about thirteen, rather con- 
vex; columella reflected ; mouth subquadrangular, effuse 
at base. 
Length 1.3, Breadth .4, of an inch. 
Observations. The striz of this species have a strong si- 
milarity to that of the Turritella lineata above described, but 
the sutures are different. In most specimens numerous lon- 
gitudinal flexed folds may be observed. 
I am by no means satisfied in placing this shell among 
the Cerithia. It has a stronger resemblance in the mouth to 
the genus JMelania, but being a marine shell cannot with 
propriety be placed in that genus. Blainville figures a shell 
(plate 21, bis. fig. 2), under the name of Potamides fragilis, 
which certainly ought to belong to the same genus with this, 
the mouth being very nearly the same. Until more species 
shall be obtained, I have forborne to create for it a new 
genus. More decisive characters may then be observed, 
