V 



g6 NEW YORK STATE MUSEUM 



Whiteavesia cumingsi nov. 



PI. 5. fig- 2, 3 



Description. Shell of the size of that of the associated 

 W . c i n c t a , but more oblique, thicker or more ventricose, less 

 higher posteriorly (one-third higher than in front) and more 

 elongate. The hinge line is slightly longer, the posterior margin 

 more rounded, the antero-basal margin more distinctly concave, 

 the anterior margin more sharply rounded and the anterior end 

 longer. Beak not as prominent, situated one-lifth of the length of 

 the shell from the anterior extremity; umbonal ridge distinct to 

 posterior margin. Surface lacking the prominent concentric folds 

 of W . c i n c t a , but showing fine concentric lines and a few 

 growth varices. Sometimes also faint postdorsal radii are seen. 



Horizon and locality. Common in the olive colored shale at Snake 

 hill, Saratoga county, N. Y. 



Remarks. Although a considerable number of specimens were 

 observed on one slab, the specimens are all so much distorted and 

 especially flattened out that they present an entirely different aspect 

 from the normal outline. We have figured also one of these flat- 

 tened • specimens (plate 5, figure 3) to facilitate recognition of 

 the species. Even if the specimen selected as type is a little com- 

 pressed laterally and therefore too ventricose and elongated, the gen- 

 eral outline will not approach that of W . c i n c t a and the 

 characteristic concentric folds of the latter have not been observed 

 in any of the cotypes. 



Doctor Ulrich considers this species as being more closely related 

 to W. subcarinata Ulrich (from the lowest Trenton of 

 Minnesota), W. saffordi Ulrich (lower Stones River) and 

 W. cancellata ( Walcott) . From W. subcarinata 

 our species is distinguished by the oblique outline, the more convex 

 posterior margin and longer anterior end ; from W. cancellata 

 by the surface sculpture. W. saffordi is a much older form. 



Orthodesma ? subcarinatum nov. 



PI- 5, fig- 5-8 



Description. Shells small, elongate, narrow and moderately arcu- 

 ate, the length from two and one-half to three times the greatest 

 posterior height and from three and one-fourth to three and one-half 

 times the height at the beaks ; valves rather strongly convex, culmi- 



