PLATE 82. 



Fig. 1. 707. 1. Megalomus canadensis. (Pag. 343.) 



1 a, b, c. Lateral views of casts, showing degrees of distortion. 



1 (/. A dorsal view where the umbones have been depressed, leaving the space between them projecting. 



1 e. Dorsal view of a cast, where the umbones have been pressed forward much beyond their natural relation. 



\ f, g. Anterior and lateral views of a small specimen, preserving the shell. 



1 A. The interior of a part of the left valve, siiowing the large muscular impression and the two smaller pits 



above, with the folds on the tliickened jrartion of the slidl. 

 1 I. The left valve of a specimen having the shell broken away, showing the numerous distinct lamii.ic of 



which it is composed. 



