DEVONIAN FAUNAS. 363 
The dimensions of the only specimen observed are: height, 17 mm. ; 
maximum diameter of aperture, 14 mm. 
Remarks.—A single specimen from the New Jersey Oriskany col- 
lection probably represents this species. It differs chiefly from the 
typical form of the species, as illustrated by Hall, in its less elevation. 
PTEROPODA. 
TENTACULITES ELONGATUS Hall. 
Plate L., Figs. 4-5. 
See, also, pp. 295 and 319. 
1859. Tentaculites elongatus Hall, Pal. N. Y., vol. III., p. 136, pl. 
6, figs. 16-21. 
1900. Tentaculrtes elongatus Clarke, Mem. N. Y. State Mus., No. 3, 
vol. III., p. 27, pl. 3, figs. 8-12. 
Description.—Shell elongate, circular in cross-section, annulate, 
gradually tapering to the apex. Annulations strong, subangular or 
rounded, two of them occupying the space of 3 mm. near the larger 
end of adult shells, while at the smaller end they are less than 1 mm. 
apart. Entire surface covered by fine, annular striae, which are most 
conspicuous in the depressions between the annulations, and are often 
nearly obsolete upon the outermost portion of the annulations. In- 
ternal casts lack the fine, annular striz, and the annulations have the 
appearance of a series of insheathed cones, with their apices toward 
the larger end of the shell. 
Some of the larger individuals attain the following dimensions: 
length, 60 to 70 mm.; larger diameter, 6 mm. 
Remarks.—This species makes its first appearance in the Coeymans 
limestone, where it is one of the rare species, and continues through 
the Helderbergian formations, but never in great abundance. It is 
most conspicuous in the Oriskany formation, where it sometimes 
occurs crowded together in great numbers. Its most usual occurrence 
is in the form of internal casts, the fine surface striae being only de- 
tected in the moulds of the exterior of the shell. 
