MIOCENE MOLLUSCA AND CRUSTACEA. 125 
features as obtained from the casts by means of gutta-percha impressions 
show a shell of about 1 inch in diameter, having a height of a little more 
than half an inch, and consisting of three volutions, exclusive of the nuclear 
apex. The upper half of the shell, counting the whorls, is smooth or with 
growth lines, while the lower half is marked by oblique rows of foliated 
spines, the rows following the growth lines, or parallel to the margin of the 
aperture of the shell, and on the outer volution are about an eighth of an 
inch apart. The spines are hollow on the face and slightly recurved. The 
volutions are moderately convex on the upper surface and the suture lines 
distinct. On the under surface the volutions are rather distinctly concave, 
the outer lip strongly receding between the outer edge and the columella, 
and being marked only by lines of growth parallel to the margin of the 
aperture. 
There can be no reasonable doubt of the proper identification of the 
forms which show the surface marked with spines, with Conrad’s figure of 
T. perarmata in his Miocene fossils, but there might perhaps of the fragmen- 
tary shells, chiefly the upper two volutions only, found in the sandy marls, 
were it not for the imprints in the clays. When, however, the two are 
examined together one is led to look for the spines of the larger ones on the 
impertect shells. On very many of them under a glass the bases of the 
spines are quite readily observed, showing their relations to the imprints of 
the more perfect ones in the clays. This leads one to the conclusion that 
the specimens identified as 7. centralis by Prof. Heilprin in his lists of the 
fossils of the New Jersey Miocene, were only imperfect examples of this 
shell, as no such specimen of 7. centralis has been observed in any of the 
collections. 
Localities and formation: In the gray sandy marls at Shiloh and Jericho; 
in the stony layers at Bridgeton, and in the clays near Bridgeton, N. J. 
From the collection at Rutgers College and the National Museum; the latter 
collected by Mr. Frank Burns. 
