44 MONOGRAPH OF DURA DEN. 



wonderment on forms of Avhich no one could tell him the names, 

 or furnish him a key to unravel the mystery of the rocks in 

 which they were entombed. 



But the master-hand of Louis Agassiz was at work also, who, 

 in his Synoptical Table of British Fossil Fishes, reported to the 

 British Association in 1843, the discovery of sixty-four generic 

 and specific forms of ichthyologic life in the Devonian system 

 of rocks alone, chiefly from the Caithness, Moray, Perth, and 

 Fife members of the Old Red. The list has been since greatly 

 extended. And now, in the last edition of Siliuia, there are 

 enumerated about forty genera, and nearly two hundi-ed species 

 of the fish and crustacean types, as found in this system of 

 rocks in Britain, Russia, and America. Agassiz notices only 

 six genera of ichthyolites, crustaceans, and plants belonging 

 to the great Silurian formation ; the list in Murchison's new work 

 shows an increase of at least fifty new genera and of five or six 

 hundred species, and all of most remarkable characters and 

 forms, chiefly of the invertebrata and the Crustacea. 



" Geologists," says M. Agassiz,* " hardly seem to appre- 

 ciate fully the whole extent of the intricate relations exhibited 

 by the animals and plants whose remains are found in the 

 different successive geological formations. I do not mean to 

 say that the investigations we possess respecting the zoolo- 

 gical and botanical characters of these remains are not remark- 

 able for the accui-acy and for the ingenuity with which they 

 have been traced. On the contrary, having myself thus far 

 devoted the better part of my life to the investigation of fossil 

 remains, I have learned early, from the difficulties inherent in 

 the subject, better to appreciate the wonderful skill, the high 

 intellectual powers, the vast erudition displayed in the investi- 

 gations of Cuvier and his successors upon the faunae and florae 

 of past ages. But I cannot refrain from expressing my wonder 

 at the pueriHty of the discussions in which some geologists allow 



* Contributions to the Natural History of the United Slates. V>\ L. Agassi/. Vol. i. 

 pp. 93, 94. Little, Brown, and Co., London 1857. 



