40 The Carboniferous Formation. 



One hundred and fifty species of fish have been discovered in 

 the coal, of which ninety-four belong to the shark and ray tribe, 

 and fifty-eight to the ganoids. They seem to have been all 

 predaceous, and often to have attained a great size. 



Among the Cephalopoda of this period the goniatite is remark- 

 able, as having been the predecessor of the ammonite which is so 

 characteristic of the secondary beds. The orthoceras and the 

 nautilus are two other important forms. 



The univalves of this period are insignificant from the paucity 

 of their individuals. The land shells in fact are so scarce, that 

 there is only one species known, and that species is very local 

 being confined to one bed in the Nova Scotia coal field. Among 

 the sea gasterops the loxonema and the euomphalus are perhaps 

 the two most characteristic genera. 



The aviculopecten among the lamellibranchiata is remarkable 

 as occasionally preserving its coloured bands, which seems to point 

 to the fact that the sea in which these shells were deposited must 

 have been shallow ; because scarcely any shells that inhabit deep 

 water possess bright colours ; and the very same shells which are 

 brightly coloured in shallow water, are without their colours when 

 procured from the deep sea. Freshwater muscles are very com- 

 mon in some of the beds of shale in the coal measures. 



The Brachiopods are, however, the most characteristic molluscs 

 of this period ; they far surpass all other shells in the number of 

 their individuals ; many of them are conspicuous for their long 

 spines, and some of them such as productus giganteus for their 

 great size. They differ in almost all respects from their represen- 

 tatives in our modern seas ; which are few in number, small in 

 size, and are never found except in deep water ; whilst we must 

 suppose those of this class from the coal, on the grounds I have 

 just stated, to have been the inhabitants of shallow water. Crinoidea 

 are, too, common in the mountain limestone, the stems being the 

 part most frequently found ; the head consists of a large cup, with 

 generally speaking short arms. 



Corals are also numerous, and sometimes form entire beds of 

 limestone ; they are characterized by possessing a quadripartite 

 arrangement of the lamellae, that is, the number of lamellae is a 

 multiple of four, and not hke our modern corals a multiple of six. 



The President then made some remarks about the power which 

 was stored up in coal. 



