TO GEOLOGY. 129 
Observations. This species is very closely allied to the 
above, but may at once be distinguished by the transverse 
striz which alternate in this. The longitudinal striz are 
not so close, nor are they imbricate. 
T. sulcata. Plate 4. Fig. 119. 
Description. Shell elevated above, rounded below, 
with numerous transverse furrows, the two superior ones 
being indistinct ; substance of the shell rather thin ; apex 
not acute; suture impressed; umbilicus ; whorls 
inflated; mouth : 
Length... . Breadth .2, of an inch. 
Observations. 'This fragment resembles so closely the 
two species above described, that I have with but lit- 
tle hesitation placed it in the same genus. It has 
apparently lost only one whorl—seven remain. It is 
rather more alternate than the preceding, and differs 
entirely in being furrowed, and having no longitudinal 
strie. Some of the parts being absent, I am _neces- 
sarily compelled to make an unfinished description and 
figure. 
GENUS TURRITELLA. Lamarck. 
T. carinata. Plate 4. Fig. 120. 
Description. Shell turrited, transversely striate and ca- 
rinate ; apex acute; substance of the shell thick; suture 
R 
