466 MR. H. BOLTON ON A MARINE FAUNA IN THE [Nov. I907, 



surface is ornamented with fine striae, which bend first forwards, 

 then backwards, along the middle of the sides and forward again, 

 from which they return to the median line. The fragment, which 

 has left its impression upon the shale, indicates a shell measuring 

 fully 100 millimetres in diameter. 



Glyphioceras carbonarium (von Euch). 



Examples of this species were found in great abundance and at 

 all stages of development. Where the shale contains ironstone, the 

 shells are well preserved and uncrushed, while in the softer shales 

 they occur only in a flattened and distorted condition. 



The outer layer of the shell is usually absent, but sufficient 

 remains in many of the specimens to show the characteristic 

 ornament of fine, transverse, crenulated striae and the tuberculated 

 umbilical margin. Among the specimens obtained from the 

 ironstone-nodules are several showing the suture-line. A few also 

 are converted into pyrites. 



Gastrioceras coronatum, Foord & Crick. (PI. XXX, fig. 22.) 



Two specimens of this rare species were met with. The only 

 other known horizon and locality at which it occurs is over the 

 Bullion or Mountain Four-Feet Mine of Bacup (Lancashire), where 

 it was found by me in 1896. Although closely allied to G. Listeria 

 the species here figured is readily distinguishable therefrom by the 

 extreme breadth and flatness of its whorls and by its deep and 

 wide umbilicus. 



Gastrioceras Listeri (Martin). 



Examples of this species are scarce and usually very small, rarely 

 exceeding a diameter of 8 millimetres. From the young forms of 

 6r. carbonarium they are distinguished by their flatter periphery 

 and wider umbilicus, which is also deep and steeply walled. 

 Examples of G. carbonarium at the same stage show a rounded 

 umbilical edge, the umbilicus itself being narrow and shallow. 



Goniatites sp. 



A small goniatite, the genus and species of which I am not able 

 to determine, is represented by a few shells not exceeding 4 milli- 

 metres in diameter. No surface-ornament can be distinguished, 

 while the umbilicus is very small. From an examination of the 

 general surface-features, I had presumed the shells to be examples 

 of Dimorphoceras Gilbertsoni ; but Dr. Foord has pointed out that 

 the suture-line seen in one specimen is not that of a Dimorphoceras. 



Fragment of a Nautiloid shell. — This is a fragment of a 

 portion of the last whorl of a Nautiloid shell. Traces of three 

 blunt tubercles are evident along the umbilical border. The 

 fragment probably belongs to a species of Temnocheilus. 



