PLATE 71. 
Fig. 1. 
Onchus deweii. 
(Pag. 320.) 
1 a. A fragment of shale, retaining the base of the spine, with about two inches of the lower portion, and 
the impression beyond this nearly to the apex. 
1 b. A fragment, retaining the impression of the base and lower portion of the spine of the preceding spe¬ 
cimen, with the higher portion of the spine itself. 
1 c. The basal portion of a much larger specimen, showing very distinctly the ornamented surface and con¬ 
stricted base. 
1 d. An enlargement from the surface of 1 c. 
