INTRODUCTION. 



The accompanying Guide to the Collection of Fossil Fishes 

 in the British Museum of Natural History has been prepared 

 in the hope that it may be found useful alike to the geologist 

 and the paleontologist. 



It has .been found more convenient to arrange the Collection 

 zoologically, rather than stratigraphically, yet every specimen 

 bears upon its label not only its name, but also the Formation 

 and locality whence it was derived. 



Moreover the fishes of the older rocks nearly all belong to 

 families and genera which are now quite extinct. The Chon- 

 dropterygii — Sharks and Eays — however, offer a remarkable 

 exception, being an order of Fishes whose persistence in time 

 probably exceeds that of any other vertebrate type ; whilst in 

 the Dipnoi, one family, at least — the Ceratodi — has come down 

 to our time from the Devonian epoch, apparently but little 

 modified* in the long lapse of geological ages. 



References will be found, at the end of the Guide, to the 

 various works in which figures and descriptions are given of 

 specimens preserved in the Collection, and which are the 

 " types," that is to say, the specimens, on which the genus or 

 species was founded. 



The student or visitor who desires intelligently to study the 

 Fossil Fishes in this Gallery will find it indispensable to com- 

 bine with it a careful examination of the fine collection of 

 living Fishes, prepared and mounted for exhibition in the 

 first North-Western Gallery of the Zoological Department, on 

 the other side of the Great Hall. 



The Collection of Fossil Fishes is exhibited in Gallery A, 

 the first of the wide North-Eastern Galleries, leading from 



* Only the teeth of these fishes have been preserved in a fossil state, 



