PLATE 105. 
Page 
Fig. 1-6. Rensselairia ovoiees. 456 
1. Dorsal valve of a full-grown individual, showing the abrupt inflection at the sides. 
2. Profile of a large shell in which the parts are pretty well preserved in all their proportions; 
the dorsal valve being partially exfoliated, and the striae not visible. 
3. Ventral view of the preceding. 
4. Dorsal view of a large specimen, which is unusually contracted at the sides on the lower 
half of the shell. 
5. A partial cast of a ventral valve, showing the form of the muscular impressions and rostral 
cavity. The forms of the dental plates and teeth are seen on each side, below the beak. 
6. A partial cast of a dorsal valve, showing a process reaching from the beak to the muscular 
impressions below. This process is the filling of the foramen, and extends from the cavity 
of the dorsal valve beneath the bases of the crural supports, coming out at the apex of 
the beak. 
