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ir 1 1. 



ON THE GENUS CTENODUS, 



A FISH FOUND IN THE TRUE COAL MEASURES OF GREAT BRITAIN. 

 By W. J. Baekas, M.E.C.S.E., L.E.C.P.L. 



[Iteud hefore tTie Hoyal Society of N.S.W,, 6 Sepiemler, 1876.] 



KisrowiNG that very few persons are acquainted with the fossil 

 ichthyology of the Carboniferous formations of Grreat Britain, 

 even in Great Britain itself, it is perhaps necessary that I should 

 state at once my reasons for introducing a paper before this 

 Society upon a subject that is apparently foreign to this Colony 

 and to all Australasia, for undoubtedly Cienodus is not found 

 anywhere in this part of the world. Ctenodus is a fish that 

 existed during the Carboniferous era of Great Britain's history 

 in comparatively large numbers, but inhabiting, so far as our 

 present knowledge extends, only a very small area of its waters. 

 Mshes of the same genus, but of different species, are found in 

 the Old Eed Sandstone, but they are very rare, and are even 

 more limited in their habitat than the Carboniferous Ctenodi, 

 judging, of course, from the scarcity of their remains that have 

 been brought to light by geological research during a goodly 

 number of years. Prior to the Devonian period we have not any 

 trace of this fish, nor have any remains been discovered in for- 

 mations that have been formed since the Carboniferous epoch ; 

 it was, therefore, considered to be a form of animal life that had 

 become totally extinct at the close of the Coal Measure era, not 

 having any counterpart in tlie different stages of the world's 

 formation after that time. Although there was not, at the time 

 of the first discovery of the remains of this fish, any known 

 living type by which its place in the order of Being could be 

 verified, the great palaeontologist Agassiz at once classified it 

 among the Fishes, for all that he had only been able to examine 

 a few dental plates. Since the time of the discovery of the 

 dental plates seen by Agassiz, extensive researches have been 

 made into the Natural History of the World as it exists at 

 present, and among these inquiries were some that were directed 

 to the ichthyology of Australian seas and rivers. It was not 

 long before the Hon. Wm. Torster obtained a fish from some 



