136 
PALAEONTOLOGY OF NEW YORK. 
The striae, originating at the suture, are first directed backward, and 
thence, gently curving over the nodes, become nearly vertical and thus 
continue to near the peripheral carina, where they are turned a little 
backward, and, passing this elevation, they are directed with a slight 
curve towards the columella. 
This fossil possesses all the characteristic features of the Linnsean genus 
Turbo, to which it was originally referred by M. be Verneuil, who described 
and named it in honor of the late Prof. B. F. Shumard of St. Louis. It differs 
so essentially from any other fossil of the Upper Helderberg formation, that 
there are no other forms for comparison. In many of its features it reminds 
one of the recent Turbo heteroclita, but it is more rotund and the columellar lip 
is solid and more extended. In its external characters it presents some 
interesting resemblances to PalcEotrochus Kearneyi. The surface striae are in all 
respects similar to those of that fossil, and their curvature is made in precisely 
the same manner. The peripheral carina is almost identical in character, 
except where it may be invaded by the nodes from above. The range of 
nodes in the Turbo is represented by the obscure elevations in similar position 
on the Troohus. In the general form of the shell, aperture and columella, 
there are no points for comparison. 
This beautiful fossil, having never been redescribed in America, has been 
nearly lost sight of, and I believe the name is scarcely or not at all known in 
our catalogues of fossils. The shell is usually silicified, and is rarely well 
preserved, though a few good specimens are known. It is nevertheless not 
rare, as is shown by numerous casts of the interior occurring in some of the 
western localities. The individuals illustrated are from the cabinet of Dr. 
James Knapp, of Louisville, and are the best specimens known to me. An 
imperfect specimen of large size exists in the collections of New York State 
Museum. 
It is worthy of notice that, among all the American fossils, there has not 
been found in the older rocks so complete representation of the genera Turbo 
and Trochus as in these examples, both of which occur in the same formation. 
