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PALEONTOLOGY OF NEW YORK. 
Hyolithes singulus, n. sp. 
PLATE XXXII A, FIG. 27. 
Form an elongated triangular pyramid, very gradually tapering from the base; 
transverse section subtriangular. The ventral face of the pyramid nearly 
plane; the dorsal face obtusely subangular in the middle, with the two 
sides sloping in a gentle convexity to the lateral margins. The lateral 
angles somewhat abruptly acute. Aperture and operculum unknown. 
Surface ornamented by fine, equal and regular transverse strirn, which are 
arched slightly backward on the summit of the dorsal face ; thence, curving 
gently forward, are again recurved close to the lateral angle or suture line. 
There are no visible longitudinal striae. 
The only specimen known is a fragment, which is imperfect at both 
extremities, but sufficient remains for the generic determination, and the 
specific characters are so unlike those of any other known in the rocks of New 
York that it may be readily distinguished. It is preserved in a gray, calcareous 
shale with numerous Brachiopoda. 
In its surface-markings it may be compared with H. striatulus of Barrande, 
as shown on figs. 47-49, pi. 12 (Syst. Silurien du centre de la. Boheme , vol. iii, 
page 92). In this respect it differs from any American species which have 
come under my observation. 
Formation and locality. In the calcareous shales of the Hamilton group, on 
the shores of Skaneateles lake, N. Y. 
A single specimen of another species of this genus has been noticed among 
the collections from the Hamilton group. The form is terete, gently curved 
(perhaps from pressure), with an acute termination, and, so far as can be 
determined, a circular or subcircular section. The specimen preserves a length 
of eleven millimetres, and the margin of the aperture is apparently entire. 
The surface is obscurely striated transversely. 
