PLATE 26. 
] 470. 1. Pentamerus oblongus. 
I a b A cast: views of the dorsal and ventral valves of a very large and gibbous specimen. 
1 cl Cardinal view of the same, showing casts of the interlaminar spaces. # 
1 d. Profile view of the same, showing strong concentric ridges of growth. 
(Pag. 79.) 
