CIRRUS tabulates. 
TAB. DCXXXVIII. 
Spec. Char. Spire conical ; in the old shell the 
latter whorls are more expanded, strongly 
marked by lines of growth ; upper part of 
each whorl flat or somewhat concave, bounded 
by an obtuse, uneven keel, the lower part 
rounded; umbilicus very large; aperture sub- 
orbicular, truncated above ; height less than 
the width. 
Syn. Cirrus tabulatus, Phill. Geol. Yorks. 225. 
pi. 13. f. 7. Morris, Catal. 142. Griffiths, 
Notice of Fossils of Mount. Lime. 20. 
Cirrus euomphaloides, Griffiths as above, 20. 
and pi. 7.f. 4. 
A rather rugged-looking shell, distinguished from Euom- 
phalus pentangulatus , M. C. t. 45, by its conical form, rough 
surface, and great size, for it sometimes reaches a foot in 
diameter. There is a peculiarity in its structure arising 
from its mode of growth : additions to the shell are made 
by thin layers, which are very thin where they line the tube, 
but instead of being continued far beyond the aperture 
to add to the length of the whorl, they are reflected against 
the edge of the lip, and at the same time much thickened, 
so that it is by the added thickness of each coat only, which 
however is considerable, that the increase of the lip takes 
place ; as the layers are composed of fibres arranged per- 
pendicularly to their planes, a section of the shell across the 
axis shows these fibres nearly parallel to its surface, or 
