GASTEROPODA. 37 
iltonia and C. lirata; being a little more ventricose than either, without the 
flattened or concave band on the upper side of the volution. 
Formation and locality. In the coarse shales of the Hamilton group at Smyrna, 
Chenango county, N. Y. 
CYCLONEMA HaMILTONLE. 
PLATE XII, FIGS. 31-36. 
Cyclonema Hamiltonice, Hall. Descriptions of New Species of Fossils, etc., p. 19. 1861. 
“ “ “ Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 47, pi. 5, fig. 16 (not 15). 1862. 
“ “ “ Illustrations of Devonian Fossils: Gasteropoda, pi. 12. 1876. 
Shell subglobose-conical; height a little more than the width across the last 
volution. Volutions four or five; apex minute and gradually expanding 
to the body-whorl which is somewhat abruptly ventricose, flattened or a 
little concave for a short distance below the suture, and the space limited 
on the exterior side by a carina, which is the first of a series, marking the 
periphery of the volution. 
Sueface marked by extremely fine lamellose lines of growth, which are directed 
backwards from the suture without bending or curvature in passing the 
carinations. The volutions, except the narrow concave space above, are 
marked by strong revolving elevated carinate lines, of which there are 
from fourteen to eighteen on the body-whorl. These carinae are usually 
simple and subequal, more or less distinctly defined, and sometimes alter¬ 
nately stronger and more subdued, or with two finer ones between the 
stronger. On each of the upper volutions there are three, four or five 
of these carinae preserved, and they are distinctly crenulated by the 
passage of the concentric striae, which are sometimes also bent forward 
on approaching the first carination. 
This species has nearly the proportions of Pleurotomaria capillaria , except in 
the more abrupt ventricosity of the body-volution. The flat or concave belt 
on the upper side of the volution, which is without revolving striae and marked 
