INOCERAMUS. 
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of the upper chalk, but is less frequent in the 
lower beds ; the hardness of the Sussex chalk 
renders it exceedingly difficult to clear the speci- 
mens, without destroying the spines. 
TheTerebratulm are very abundant; a few of the 
common species are figured below. 
1. 3. Terebratula semiglobosa. 
2 . Terebratula carnea. 
4. Terebratula plicatilis. 
5. Terebratula octoplicata. 
6. 7. Terebratula subplicata. 
INOCERAMUS. 
The shells 'of the genus Inoceramus are very 
remarkable, and ten species occur in the chalk of 
the South of England. These shells are more 
