32 
PALAEONTOLOGY OF NEW YORK. 
not often well preserved. In some of its variations it simulates Platyostoma ; 
but in all phases it differs from that genus in the characteristic expression of 
the spire. Although a considerable number of individuals have been examined, 
it does not appear to be an abundant form, nor to have any wide distribution. 
Formation and locality. In limestone of the Upper Helderberg group, in 
Onondaga county, N. Y. The specimens have all been communicated by 
Prof. E. A. Strong. 
MACROCHEILUS, Phillips. 
Macrocheilus Hebe. 
PLATE XII, FIGS. 4-7. 
Macrocheilus Hebe, Hall. Descriptions of New Species of Fossils, etc., p. 20. 1861. 
“ “ “ Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 48, pi. 4, fig. 1. 1862. 
“ “ “ Illustrations of Devonian Fossils: Gasteropoda, pi. 12. 1876. 
Shell turreted, subfusiform, length less than twice the diameter. Yolutions 
five or six, upper ones minute, the last two ventricose; one-half the 
height of each volution showing above the suture. Shell thick on all 
parts, especially near the aperture. Aperture longitudinally suboval, 
somewhat pointed below. 
Surface marked by extremely fine lines of growth. Height of the largest 
individual seen, a little more than three-fourths of an inch. 
This shell has all the characteristics of the genus Macrocheilus as it occurs 
in the Coal measures, and is one of two well-marked species of the genus that 
I have observed in the Hamilton group. It bears a near resemblance to M. 
Newbcrryi, of the Coal measures; but the last two volutions are more ven¬ 
tricose, the suture-line close, while the shell, of less length, has one more 
volution. From the M. ventricosus it differs in the larger and less attenuated 
spire, and in its last two volutions being ventricose. It appears to be an 
extremely rare species, as among all the later collections made in Central New 
York, no specimens of it have been observed. 
Formation and localities. In the Goniatite limestone of the Hamilton group, 
at Manlius, N. Y., and in the arenaceous shales near Hamilton, N. Y. 
