161 



considerations, this rock would be more properly classed with the 

 tertiary formations than the secondary. Below the Chalk not one i"e- 

 cent species has been met with ; in the Wealden Beds, the Oolitic 

 Beds, and the Lias, even the genera are all different from those in the 

 chalk. Below the lias, two out of the four orders, under which M. 

 Agassiz comprehends all the fishes that are known, viz. the Cycloi- 

 dean and the Ctenoidean, entirely vanish, while the other two orders, 

 rare in our days, suddenly appear in great numbers, together with 

 large sauroid and carnivorous fishes. Of the fishes that occupy the 

 Transition Rocks few have been brought to light, and no peculiar cha- 

 racter has yet been affixed to them. In general the more ancient 

 fishes are the best protected by scales. Those which are more an- 

 cient than the green sand exhibit none of those marks by which we 

 can determine in the fishes of our own times whether the water in 

 which they live be fresh or salt 5 the species always changes with the 

 formation, and frequently, as we see, the genus also. It would ap- 

 pear, therefore, that greater changes take place in the higher order 

 of animals than the lower in equal periods of time. 



Your award of the Wollaston medal to this eminent naturalist 

 has led to the most advantageous results. By that award M. Agassiz 

 having been induced to come over to this country, has received in all 

 quarters that distinction which his superior knowledge and personal 

 character and deportment justly deserve. With a view to enable 

 him to devote a larger portion of time to the study of fossil 

 Ichthyology in Great Britain, the Association for the Advancement 

 of Science voted to him at Edinburgh the sum of 100/. During 

 his subsequent excursions in various parts of England and Ireland 

 he had ample opportunities of visiting whatever collections have 

 been made in that department of natural history to which he devotes 

 himself J and every one was happy to transmit to our apartments 

 at his request any specimens which he wished to figure. In the 

 very short space of time to which his stay in this country was 

 necessarily confined, M. Agassiz was enabled to add to the very 

 large number of species which he had already examined, no less 

 than two hundred that were entirely new to him j these were placed, 

 immediately as they arrived, in the hands of an artist from Neufcha- 

 tel, acting under M. Agassiz's direction. Such are the facilities 

 and advantages which Associations like ours supply to those whom 

 our motto designates as true sons of science! 



Sir Philip Egerton has drawn out for us a Catalogue of a rich Col- 

 lection of Specimens formed by himself and Lord Cole in the caves 

 of Franconia and the Hartz Mountains. In the cavern at Galenreuth, 

 now closed against visitors, it was their good fortune to obtain several 

 bones of the fossil bear, which the late Baron Cuvier required to com- 

 plete the skeleton of that animal. Many of them appear to have been 

 scratched, but none gnawed. In all these caverns, recent bones re- 

 terrible to various animals, accompany the fossil ; and in some of 

 them have been found old coins, iron implements, and fragments of 

 rude pottery. 



To a work which I shall have occasion to bring under your notice 



