164 
which the Rev. Mr. Steinhauer collected, along with 
Pecten papyraceus * (tab. 354), about two miles and a 
half north of Halifax, on the road to Bradford, where the 
Limestone balls are sufficiently abundant to repay the ex- 
pense of burning. The stratum of Shale that contains 
them extends northward beyond Bradford to Idle, in 
the neighbourhood of Calverly and Farsley near Horse- 
forth. The stratum may be thus traced from Middleton 
to near Leeds, and perhaps further. We expect at some 
future period to see an account of this district from the 
pen of E. S. George, Esq., who has examined it parti- 
cularly, and traced the Pecten papyraceus (that seems to 
accompany Am. Listen) through a long course. 
AMMONITES longispinus. 
TAB. DL— fig. 2. 
Spec. Char. Discoid, thick, with two concentric 
rows of spines upon each side ; whorls few, 
half exposed, front round. 
A nearly plain shell, consisting of two or three whorls 
with long spiniform tubercles on each side : the aperture 
would be orbicular were it not rather deeply indented 
by the preceding whorl ; the greatest length of the aper- 
ture is about 3-5ths of the diameter of the shell. 
Found near Weymouth. A considerable portion of the 
pearly shell remains mingled with sparry Carbonate of 
Lime, and filled with indurated Marl, and a little Iron- 
pyrites. 
* Anomia Pecten Gmel. 3342. Pectinites membranaceus, &c. 
Lister , Anim, Angl. <243. t. 9. f. 49. 
