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Description of New Fossils from Ohio and Kentucky. Tet 
also upon the matrix from which the shell was taken, collected by Dr. 
Rk. M. Byrnes, in whose honor I have given the specific name, in the 
upper part of the Hudson River Group, near Weisburg, Indiana, and 
now belonging to his collection. It is peculiar in preserving the mark- 
ings of the spines-which covered the surface, in the matrix, and also 
preserving the bases of them on the shell, which may be readily ob- 
Served with an ordinary magnifier. It will be distinguished from 
other species by the fact that its thickness is only half its height, and 
only one fifth its length, as well as by other peculiarities. As this 
species was covered with numerous spines, it becomes interesting to 
know whether other species in the same venus were also thus orna- 
mented. 
DESCRIPTION OF NEW FOSSILS FROM THE LOWER 
SILURIAN AND SUBCARBONIFEROUS ROCKS OF 
OHIO AND KENTUCKY. . 
By A. G. Wertuersy, A. M., 
Prof. Geology and Zoology, University of Cincinnati. 
CEPHALOPODA. 
Cotpoceras, Hall, 1850, 3d Reg. Rep., N. Y., Birdseye and Black river. 
CoLPocERAS CLARKEI, nov. sp. (Plate IL., figs. 5, 5a.) 
Shell very gradually tapering, composed of equal septa, obliquely 
united at the sides, with a gently rounded convexity pointing to the 
posterior extremity on the dorsal surface, fig. 5, Pl. II., and an acute 
angle pointing toward the body chamber on the ventral surface, fig. 5a, 
Pl. II. The septa are separated by slight semi-sutures, which give the 
shell a somewhat corrugated appearance, as may be seen in the figures. 
The obliquity of their line of junction throws the point of the ventral 
angle of each segment more than three times the width of the segment 
itself, in front of its posterior dorsal margin. The septa in the speci- 
men figured have a width of 9 mm. ? 
In section the specimen is seen to be slightly elliptical, owing to the 
shortening of the dorso-ventral diameter, which measures 20 mm., 
while the transverse measures 234 mm. Nine segments of the shell 
measure two and one half inches, 624 mm., in length, with an almost 
