OF DENISON UNIVERSITY. 
35 
Edmondia. No traces of radiating lines are preserved, but the con- 
dition is such as to explain their disappearance. 
Our specimen is rather less ventricose than that figured by White, 
but is also smaller. Length, .52, height, .40. 
Genus Pleurophorus, King. 
1. Pleurophorus tropidophorus , Meek. 
(Plate IV, Fig. 15.) 
This pretty shell is not uncommon at Flint Ridge. I am not sure 
that there are not two closely related species differing chiefly in size. 
2- Pleurophorus suheostatus, M. and w. (?) 
(Plate IV, Figs. 16 and i6a.) 
We have a number of small specimens which vary so much 
among themselves that the variableness may account for some discrep- 
ancies between them and the description of Meek and Worthen. 
Ours is a smaller form and the larger examples have the sinuous lower 
outline of P. subcostatus. A very much smaller and more compact 
form figured on the same plate, Fig. 7. may be the young of the 
same species. 
Genus Cypricardina, Hall. 
Hinge unknown, shell elongate trapezoidal, moderately com- 
pressed, beaks anterior or sub-anterior, slightly prominent, surface 
marked by rather prominent concentric plications or striae. (Hinge 
with well deYeloped hinge- plate, with one linear tooth in one valve 
and two in the other, and other, minute linear teeth shorter than the 
others, Synopleura^ Meek. ) 
Cyprieardina (?) earhonaria, Meek. 
(Plate IV, Figs. 17 and 18.) 
This shell was described from the locality whence our specimen 
came, so that it may- be best simply to quote the description given by 
Meek: Shell small, longitudinally oval, less than twice as long as 
high, the widest (highest) part being under the posterior extremity of 
