PLATE II. 



Page. 

 Figs. 1 to Ic. Productus semireticulatus var. hermosanus 358 



A very characteristic specimen. The ears are somewhat broken away. 



Fig. 1. Ventral valve seen from above. 



la. Anterior view. 



lb. Posterior view. 



Ic. Side view. 



Hermosa formation: Between Hermosa Creek and Animas Valley, Durango quadrangle 



(station 2204). 



Figs. 2 to 2b. Phoductus semireticulatus var. hermosanus 358 



Another somewhat smaller specimen of the type common in the Hermosa formation. 



Fig. 2. Ventral valve seen from above. This figure represents the specimen too much 



tilted downward and forward. 



2a. Anterior view of the same. 



2b. Side view. The pose of the specimen is not quite correct, the near cardinal angle 



being evidently somewhat depressed from the line of sight. 



Hermosa formation: Hermosa Creek (?), Durango quadrangle (station 2333). 



Figs. 3 to 3b. Productus semireticulatus var. hermosanus 358 



A rather small dorsal valve which is somewhat imperfect. 



Fig. 3. Specimen seen from above. Possibly the cardinal angles should be restored as 



more projecting. 



3a. Side view. 



3b. Posterior view. 



Hermosa formation: Animas River, Durango quadrangle (station 2335). 



Figs. 4 to 4b. Productus semireticulatus var. hermosanus ., 358 



Ventral valve of a finely striated type more or less intermediate between this species and 



Productus inflatus, to which, on the whole, I am disposed to regard it as nearer related. 



Fig. 4. Specimen seen from above. 



4a. Posterior view. 



4b. Side view. 



Weber formation: Weston Gulch, Leadville district (station 2268). 



488 



