10 /' /' ihes. 



throw do light upon the structure of the tail, the lower part of 

 the individual being wanting. Ii, however, renders it almost 

 certain that the species cannot be comprehended in the genus 

 / rynotus as described by Agassis, and it will not unlikely 

 prove the representative of another new genus. 



It has "i late years been generally admitted that the sand- 

 stone from which these fishes are derived is of much later date 



than the old red sandstone, to which it was once referred, and 



these remains confirm this belief. The Palaonisci of Europe 

 have never been found below the coal measures, while they ex- 

 tend upward to the copper slate of the zechstein or magnesian 

 limestone. In the case before us, we find a species of PaUeo- 

 nuctu accompanied by a fish, the structure of whose tail ap- 

 proaches thai of the PholidophortMi and of other fishes never 

 found below the lias. This fad would seem to imply for this 



formation, even a higher situation in the series than that which 



i> nom assigned it l»_\ geologists. A careful and extended ex- 

 amination of the fossil fishes of this deposit, undertaken 1>_\ able 



ami experienced naturalists, is much needed, and would pro- 



bably decide the question of its relative age. 



