1G2 CJUIDE TO THE FOSSIL INVERTEHBATE ANIMALS. 
Gallery 
VII. 
Table-case 
2 . 
lias three or four whorls closely coiled in one plane. The 
Ordovician and Silurian rocks of Bohemia furnish several 
s])ecimens of a Hat closely coiled shell, called Barrandeoceras, 
after the great palaeontologist of Bohemia ; an example from 
])udley is also shown. 
The coiled cone of the preceding shells is generally 
circular or elliptical in section, and has a smooth or slightly 
ornamented surface. There are others in which the cone is 
ihittened or grooved, and the surface bears more marked 
ornament. Thus Triyonocentit, found in the Carboniferous 
Fig. 1)2. — Palaeozoic Nautiloidea. a, Ophidioceras simplex, Silurian, 
Bohemia, b, llercoceras mirum, Devonian, Bohemia, c, Aphclcceras 
miitabilc, and d, Vestinautilus multicarinatus. Carboniferous Lime- 
stone, Ireland. All slightly less than natural size. (From Foord.) 
