44 
BULLETIN OF THE LABORATORIES 
lie at least sixty feet below congl. 1 . Shell nearly semi-circular ; mod- 
erately convex; length 4-3-2 tim:^s the height; valves of nearly 
equal convexity. Hinge-line considerably extended with acute ears, 
which are sometimes mucronate. Ventral valve convex with a rather 
prominent beak and strongly curved striated area; greatest convexity 
near the beak ; lateral portions depressed ; sinus narrow, but rather 
deep; surface marked by 40 rounded plicae which are dichotomous, 
and of which about four occupy the sinus, which is triangular m sec- 
tion, especially near the beak. Area moderately narrow and strongly 
inclined, with a broad triangular area which is striate. Dorsal valve 
only moderately convex, laterally depressed, most convex above the 
middle, fold very inconspicuous, scarcely elevated, with two pairs of 
plicae produced by bifurcation of the two primary ones. Dichotomy 
of striae of both valves very irregular. Surface concentrically striate, 
sometimes with concentric folds also. Found in the lowest horizon of 
Licking Co. Its range being 20 feet, so far as observed. 
This species was first described from the so-called Chemung of 
Missouri. Later, Prof. Hall, in his Iowa Report describes specimen 
from rocks of the Hamilton age, while Prof. Winchell noted its occur- 
rence in Waverly strata, at Sciotoville, O. 
The casts show peculiar internal structures which may be of 
assistance in destinguishing the species. 
Spirifer striatiformis, Meek. 
(Plate III, Fig. 26; Plate VI, Figs. 6-7.) 
Undoubted and typical specimens are found in our upper Waver- 
ly, well toward the summit of the series. The illustrations in the third 
volume of the Ohio Palaeontology convey a good idea of this shell. 
Isolated dorsal valves, however, resemble the shell called in Ohio, S. 
carteri, and are sometimes so-called. Eight to twelve plicae occupy 
the mesial fold. The fine radiating striae, when preserved, are good 
specific marks. 
Shell of medium size ; semi-oval in outline, only moderately con- 
vex mesially, rather flat toward the sides; hinge-line equal to greatest 
width or sometimes less, often slightly mucronate ; lateral margins 
generally making with the hinge-line about a right angle. Ventral 
valve much more convex than the dorsal ; beak strongly incurved ; 
