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ORTHOCERA fusiformis. 
TAR. DLXXXVIII.- figs. 1.&2. 
Spec. Char. Fusiform. 
A middling-sized Orthocera : it is smooth, round, and 
rather rapidly tapering towards both ends, the open end 
truncated ; the siphon nearly central ; the last chamber 
is large, commencing at the widest part. 
Occurs in the Black Limestone of Ireland, particularly 
in Queen’s County, where it is, in common with other 
fossils, often variously curved (See a portion at fig. 2.) 
by some change the rock has undergone subsequently 
to its being deposited. The last chamber is rarely found. 
The specimen figured (fig. 1.) enriches the collection of 
W. Gilbertson, Esq., who obtained it near Preston in 
Lancashire, from a Limestone corresponding in its con- 
tents very closely with that of Ireland. A great portion 
of the last chamber has been filled with loose earthy 
matter that settled to one side, and being easily removed, 
has left the last septum with the opening into the siphon 
very distinct : a few minute crystals of quartz are scat- 
tered over the surface. 
