352 Descriptions of some Shells, &c. 
Genus Turritella, Lam. 
T. interrupta. Fig. 7. 
Shell, small, subulate, brownish : volutions, about ten, almost flat, 
with about twenty two transverse, obtuse, ribs, separated by grooves 
of equal diameter, and with about fourteen sub-equal, impressed, 
revolving lines, which are arranged in pairs, and entirely interrupted 
by the ribs: below the middle of the body whirl, the ribs become 
obsolete, and the revolving lines continuous: sutures, made quite 
distinct by a slight shoulder to each volution: aperture, ovate, an- 
gular above, regularly rounded below, about one fifth the length of 
the shell: right lip, sharp, indistinctly sinuous. 
Length, 0.22 of an inch. 
Breadth, 0.07 do. 
Inhabits Newport harbor, (R. I.) Obtained by the dredge. 
This shell resembles in some respects the Turbo elegantissimus 
and the Turbo simillimus of Montague—the Turritella equalis of 
Say, and the Turritella laqueata of Conrad, but, besides other dif- 
ferences, none of these are described as having the interrupted re- 
volving lines of this species. 
Genus Cerithium, Brug. 
C. reticulatum. Fig. 8. 
Shell, small, turreted, oblong-conical, having a granulated surface 
from the crossing of longitudinal obtuse ribs, and prominent spiral 
strie: ribs, about twenty, soon becoming lost below the middle of 
the body whirl, and presenting distinct rows of granules on the spire: 
spiral str*e about six on the penultimate and antepenultimate whirls, 
five on tue next above, and gradually lessening in number to the 
apex, very rarely with any intermediate smaller strie; the spiral 
row of granules next below the suture, rather larger, and forming @ 
slight shoulder to the volutions; about six, raised, revolving lines, 
obsoletely granular, below the middle of the body whirl: volutions 
about nine, slightly convex above the body whirl: sutwre; impress- 
ed: aperture, oblique, sub-ovate, acutely angular above, widely 
rounded below, less than one third the length of the shell: labium, 
concave: labrum, slightly waving in accordance with the ridges and 
valleys of the strie, and not thickened: canal, a little recurved. 
Length, 0.28 of an inch. 
Breadth, 0.10 do. 
Tnhabits Narraganset roads, (R. I.) and Boston harbor, (Mass-) 
