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. Listeri) through a long course. 



AMMONITES longispinus. 

 TAB. Bl.~fig 2. 



Spec. Char. Discoid, thick, with two concentric 

 rows of spines upon each side ; whorls few, 

 half exposed, front round. 



A NEAiiLY 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 6r;rte/. 3342. Pectinitesraembranaceus, &c. 

 Lister, Anim. Angl.243. t. 9. f. 49. 



