PLATE 5 (bis). 
Fig. 1. 46. 3. Macturea macna. (Pag. 26.) 
1 a. An obliquely vertical section of the fossil, passing nearly through the centre of the spire above, but more 
on one side below, so as to escape the umbilicus. 
1b. A vertical section of the outer volution : a common appearance upon the weathered surface of the rock 
at Chazy. 
1c. An unusually large specimen of the same species; the surface worn so as to obliterate the striw, and 
obscure the first volutions. 
