238 NORTH STAFFORDSHIRE COAL FOSSILS. 



FAMILY LEPIDOSTEI, AGASSIZ. 

 GENUS PAL^EONISCUS, AGASSIZ. 



This genus is the most abundant not only in species 

 but in individuals of any genus of fishes found in these 

 coal-measures. From the great number of remains found, 

 it would appear that the ancient carboniferous seas swarmed 

 with Palasonisci. No doubt they filled important offices in 

 the then economy of nature, and served as food for many 

 of the larger ganoids which co-existed with them. The 

 Deep mine ironstone shale is especially rich in Palasonisci. 

 The specimens are found on the surface of the lamina?. 

 They invariably retain the beautiful enamelled surface of 

 the original ganoine. Many of the examples which have 

 been found present a lateral view, with the various fins 

 outspread and in a good state of preservation. Examples 

 with the body bent, the mouth extended to the uttermost 

 stretch, and presenting an appearance as if the fish had 

 died in agony are frequently found. Individuals showing 

 the ventral aspect occasionally occur. In a short appendix 

 to a report on " The Distribution of the Organic Remains 

 of the North Staffordshire Coal-Field," * mention is made 

 of the occurrence of P. Robisoni (Ag.), P. ornitissimus (Ag.), 

 P. monensis (Eg.), and P. striolatus (Ag.) A careful compari- 

 son of these species with a large number of specimens both in 

 our own as well as in other collections, convinces us that 

 Dr. Young was in error in placing these species in the list 

 of fishes of these coal-measures. Admitting, as we do, that 

 the resemblance is strong between the above-named species 

 and specimens of Pala3onisci which have been collected, we 

 think the specific distinction is such as to warrant their 



* Brit. Asso. Report, vol. for 1865, p. 317. 



