OF DENISON UNIVERSITY. 
65 
Waverly from the Chemung form is futile. Hall states that the pres- 
ent species differs from S. chemungensis, var. quadrangularis in that 
the base is more broadly rounded and ihe anterior portion is more ex- 
panded below, giving the shell a more equilateral appearance. This 
is not appreciably so in our specimens, though considerable variation 
is seen. The close relation between the Chemung and Waverly is 
here obvious, 
Plate IX, Fig. 20 represents a form still more like the Chemung 
species. 
Schizodus cuneus, H. 
f Plate V, Fig. 15. ) 
This little species is not rare in the freestone of middle Waverly, 
and may be easily recognized by its triangular form and small size. 
Schizodus inedU^nsis, ■ Meek. 
(Plate I, Fig. 16. ) 
The figured specimen is imperfect, but characteristic specimens 
are common in the freestone with the above. 
Orthonota r ecti dor salts , Whi, 
(Plate X, Fig. 1.) 
Shell of medium size, elongate, moderately convex. Hinge and 
ventral margins nearly straight and nearly parallel ; beak sub-terminal ; 
anterior margin gradually curved to above one- half the height, then 
abruptly curved and slightly concave to the beak, which is very slight- 
ly elevated. Posterior margin ungulate curved, making an angle of 
about 110° with the hinge line and passing by a more gentle flexture 
into the ventral border. The greatest thickness is about one-third 
from the anterior, the surface is evenly convex along a line passing to- 
ward the postero ventral angle. There is a rather deep groove pass- 
ing parallel to the hinge from the beaks'. 
