S99 



the Halifax Coal,) to the very next group of animals 

 succeeding the Vertebrata; the highest of the invertebrate 

 division being the Cephalopodous Mollusca. In the Halifax 

 Coal we find the Goniatites Listeri throughout its entire 

 course, though not in equal perfection ; for while in some 

 districts the shell is perfect, and, owing to the presence of 

 iron pyrites, has a beautiful metallic lustre, at other places, 

 as for instance at Moor Allerton, where the coal is reduced 

 to a thin bed of black-looking earth, the shells are com- 

 pressed and nearly flat. Capt. Thomas Brown enumerates, 

 in the Transactions of the Manchester Geological Society, 

 G. mutabiles and G. calyx, from the Coal shale near Tod- 

 morden. In the Catherine Slack Coal beds, near Halifax, a 

 species of Nautilus has been discovered, which is described 

 and figured in the Proceedings of this Society, page 182, by 

 Dr. Inglis, under the name of Nautilus Rawsoni. In the 

 Museum of the Leeds Philosophical and Literary Society 

 I have since detected a specimen of this shell, which 

 has been there many years. In the Museum of the West- 

 Riding Geological and Polytechnic Society is also a portion 

 of another specimen, found in excavating the tunnel for 

 the Sheffield and Manchester Railway, at Dunford Bridge. 

 Another genus of this group, Orthoceras, occurs in the 

 same bed, but is not very extensively distributed. This 

 is represented by the Orthoceras Steinhaueri found in the 

 Halifax Coal at Holmfirth ; and remarkable as it certainly 

 is, without any break in the classification, we next arrive 

 at the order which immediately succeeds the Cephalopoda, 

 the Trachelipodan Mollusca, which are represented by the 

 Melania Greenwoodi, from the roof of the Dulesgate Coal 

 at Todmorden. Here, then, we arrive at the first disruption 

 in our classification, as I have no knowledge of any examples 

 of Gasteropodous Mollusca being found in this district. But 

 very singular again, the next shells which claim our notice are 

 of marine origin, and belong to the Acephalous Mollusca. 



