PLATE III 



Page. 

 Figs. 1 to lb. Productu.s inflatits 359 



A typical ventral valve of the form referred to McChesney's species. 



Fig. 1. Specimen seen from above. 



la. Side view. 



lb. Posterior view. 



Weber formation (?): Horseshoe Mountain, Leadville district (station 2281). 



Figs. 2 to 2a. Productus inflatus 3.59 



A ventral valve in which the cardinal angles have been broken away. 



Fig. 2. Specimen seen from above. Thefigureshowsthe strife as proportionally too coarse. 



2a. Posterior view. 



Weber formation (?); Horseshoe Mountain, Leadville district (station 2281). 



Fig. 3. Producti;s inflatus 359 



A specimen in which both valves are retained in place. 



Dorsal view. 



Weber formation (?): Horseshoe Mountain, Leadville district ( station 2281) . 



Figs. 4 and 4a. Productus gallatinensis 361 



A specimen of the ordinary size and character. 



Fig. 4. Anterior view. 



4a. Side view. 



Hermosa formation: Near Cascade Creek, in the Engineer Mountain quadrangle (station 2247). 



Fig. 5. Productus gallatinensis 361 



Another characteristic specimen, somewhat smaller than the foregoing and of nnsymmet- 



rical growth. 



Posterior view. The specimen is represented as too much tilted forward, by which the 



height appears unnaturally diminished. 



Hermosa formation: Near Cascade Creek, in the Engineer Mountain quadrangle (station 



2247). 



Figs. 6 to 6b. Productus gallatinensis 361 



Another ventral valve belonging to this species. 



Fig. 6. Anterior view. 



6a. Posterior view. In this case also the tilting of the specimen causes the height 



to appear less than it should be. 



6b. Side view. 



Hermosa formation: Bear Creek, in the Durango quadrangle (station 2213). 



Fig. 7. Productus gallatinensis 361 



A large ventral valve, somewhat distorted through compression. 



Posterior view. 



Hermosa formation: San Juan region (station 2233). 



490 



