President's Address. 145 



and which were so largely to contribute to his world-wide 

 reputation, Agassiz brought to bear the indispensable qualifi- 

 cations of an intimate acquaintance with recent ichthyology 

 as well as with zoology and comparative anatomy in general . 

 And in pursuing his investigations into the ichthyology of 

 bygone ages, he soon became aware that no satisfactory place 

 could be found in the Cuvierian system of classification for an 

 extensive array of extinct fishes, which prevailed especially 

 during the great palaeozoic and secondary epochs. They 

 bore affinity both to the sturgeon, classed by Cuvier among 

 the Pisces cartilaginei, and to the American Zepidosteus and 

 African Polypteriis, whose place was then considered to be in 

 the Malacopterygian or soft-finned division of the Pisces Ossei. 

 The point in their configuration, by which Agassiz was more 

 especially struck, was their possession of strong, bony, and 

 usually glistening scales, the last-mentioned peculiarity sug- 

 gesting the term *' ganoid," as expressive of their distinctive 

 aspect. The study of these ancient " enamelled-scaled " fishes 

 seems to have formed the spring to the conception of his new 

 classification of fishes, according to their scales, into the four 

 orders of Gcinoidei^ Placoidei, Ctenoidei, and Cycloidei. Work- 

 ing on the basis of this classification, he commenced the pub- 

 lication of his great work, and had already, as he tells us, 

 become acquainted with six hundred species of fossil fishes, 

 when, in 1834, he visited Great Britain for the first time, and 

 his studies received a fresh impetus from the wealth of new 

 forms which he found in English collections. In Scotland, 

 too, collectors had been bestirring themselves, for besides 

 what we have already noticed as having been done by Messrs 

 Sedgwick and Murchison, and by Dr Hibbert and the Eoyal 

 Society of Edinburgh, Professor Traill had made a valuable 

 collection from the Old Eed Sandstone of Orkney ; Dr Knight 

 of Aberdeen from the same formation at Gamrie; Lord Greenock 

 had discovered the richness, in fish-remains, of the carbonifer- 

 ous shales at Wardie ; and many Scottish specimens had also 

 been collected by Professor Jameson, Mr Jamieson Torrie, 

 Professor Buckland, and others. 



The British Association met that year at Edinburgh, and 

 on Wednesday, the 10th of September, Agassiz was intro- 



