viii INTRODUCTION. 



Pendock, not only seized every opportunity of rescuing - 

 isolated discoveries from destruction and oblivion, but also, 

 by his numerous writings, instigated others to pursue the 

 same course. The late Dr. D. M. McCullough, of Aber- 

 gavenny, obtained a large series of Pteraspidian shields 

 from that neighbourhood, presenting all the finer examples 

 to the British Museum ; and Monmouthshire was also 

 systematically explored by the late Mr. J. E. Lee, F.G.S., 

 who likewise added all his discoveries to the National 

 Collection. 



The Upper Old Red Sandstone of Shropshire does not 

 yield many fossils, but a species of Bothriolepis was obtained 

 from these beds in 1862 by Messrs. Baxter and Weaver 

 Jones ; and these specimens, with the scales and teeth of an 

 undescribed Rhizodont ganoid from the same formation, 

 are now preserved in the British Museum. 



The fish-bearing character of the Lower Old Red Sand- 

 stone of the Scottish Highlands seems to have been first 

 discovered by the late Hugh Miller, of Cromarty, and 

 Robert Dick, of Thurso, whose combined collections are 

 now, for the most part, preserved in the Museum of Science 

 and Art, Edinburgh. The late Lady Gordon Cumming 

 made extensive excavations at Lethen Bar, Nairnshire, 

 providing many specimens for description by Agassiz, and 

 forming the fine collection at present in the Forres Museum. 

 An early worker in the flagstones of Orkney was Dr. T. S. 

 Traill, whose collection furnished many types of species 

 described by Agassiz, and was sold on the founder's death 

 to various collectors ; several of the missing types have 

 been recognised by the authors of the present work 

 among Orkney fossils that have finally reached the British 

 Museum, but many important specimens still remain to 

 be re-discovered. About twenty years ago the late 

 Mr. Charles W. Peach obtained a large series of specimens 

 from the flagstones of Wick and John o' Groats, at present 

 forming part of the collections in the British Museum, the 



