INTRODUCTION. ix 



Museum of Practical Geology, and the Museum of Science 

 and Art, Edinburgh ; and, in 1861, the Rev. J. M. Joass, 

 LL.D., of Golspie, discovered a new fish-bearing horizon 

 at Edderton, near Tain, Ross-shire. Within the last few 

 years, Mr. Jex, collector to Mr. Damon, of Weymouth, 

 has made successful excavations in the well-known nodule 

 beds of Lethen Bar (Nairn), Tynet Burn (Banff), and 

 Gamrie (Banff), and thus greatly enriched the British 

 Museum and the Museum of Science and Art, Edinburgh ; 

 and the Worcester Museum owes a small but fine series of 

 Thurso fossils to the generosity of Dr. Erlin Clarke. The 

 Lower Old Red Sandstone of Forfarshire has been explored 

 by Mr. James Powrie, F.G.S., of Reswallie, whose fine 

 collection contains the types of several new genera and 

 species described by himself and Professor Ray Lankester, 

 F.R.S. ; the late Rev. Hugh Mitchell also obtained several 

 specimens from the same beds ; and Mr. Jex has more 

 recently collected a fine series, now preserved in the British 

 Museum and the Museum of Science and Art, Edinburgh. 

 The Upper Old Red Sandstone of Elgin and Nairn 

 yields many fragmentary remains of fossil fishes, and the 

 early collections of Robertson, Malcolmson, and Patrick 

 Duff, furnished several of the type specimens described 

 by Agassiz. The Robertson Collection was dispersed by 

 auction in London, about 1854, and some of the specimens 

 were purchased by the British Museum, while others 

 ultimately reached the Geological Society ; several of the 

 types, however, are missing. The Malcolmson Collection 

 forms a small series in the Forres Museum, and that of the 

 late P. Duff is now for the most part incorporated with 

 the collection of Mr. Powrie, a few specimens being also 

 in the Geological Society's Museum. About forty years 

 ago, Major Lambert Brickenden collected a fine series of 

 Holoptychian and Asterolepid remains from Scat Craig, 

 still preserved in his private cabinet ; and quite recently 

 Dr. R. H. Traquair has secured for the Edinburgh Museum 



