HYDE: CAMAROPHORELLA. 53 
muscles. The crura are a continuation of the hinge plate and are 
inserted on its side near the anterior margin. They are long and 
slightly curved. The primary lamellae converge dorsally, diverge 
anteriorly, converge ventrally, and diverge posteriorly as in jVIeristella. 
There are from eight to ten whorls of the spiral ribbon to each cone. 
The jugum is placed on the primary lamellae at about one third their 
length from the crura and rests on the high median septum of the 
brachial valve. It appears to consist of a curved saddle between the 
two lamellae, in shape not unlike the saddle of Athyris but much 
smaller, on which the remainder of the jugum has been laid down as a 
single plate or possibly by two separate periods of spiculization. The 
lamellae of the jugum are placed at a sharp angle to each other, the 
outer portions hing just without and parallel to the primary lamellae. 
They recurve and are attached to the jugum near its base. 
Surface, as far as known, marked by fine concentric and radiating 
striae. 
Disfribution. — From the Kinderhook at Burlington, Iowa, and in a 
mixed Osage-Kinderhook fauna in the Waverly at Sciotoville, Ohio. 
In 1870, Professor Alexander Winchell ('70, p. 254) described a 
species from Sciotoville, Ohio, under the name CenironeUa f flora, 
but, as previously stated, he clearly had before him two different 
species, one of which was the form now under discussion. The 
material was loaned to him by Professor E. B. Andrews and was 
collected from the same bed from which the present material was 
obtained. The writer has an intimate acquaintance with the fauna 
of this bed and there are only two species out of some seventy-five 
found therein to which the characters named in the following descrip- 
tion can be applied, both common forms, Cranaena suheUiptica Hall 
and Clarke (described originally as Cryptonella) and the Camaropho- 
rella described herein. Following are Winchell's description and re- 
marks in full: 
"Shell broadly ovate, rather rectilinear along the cardinal slopes, 
broadly and slightly sinuate, or not, along the ventral commissure; 
general form of each valve a segment of a sphere. Surface of shell 
very finely and sharply striate both longitudinally and concentrically. 
"Length, fifteen-sixteenths of an inch; breadth, fourteen-sixteenths; 
thickness of both valves seven-sixteenths. 
"This species is broader and less rostrate than C. AUei, Win. (Proc. 
