ANJflVERSARY ADDEESS OF THE PRESIDENT. Ixxvii 



supposed to exist between these difFerent types has been removed 

 by means of the fossil remains of the now extinct Elasmotheria, 

 Palaeotheria, Lophiodonta, Anthracotheria, &c. The object of this 

 memoir is to describe more fully than has yet been done the 

 peculiar zoological position of the genus Lophiodon, and its con- 

 nexion with, and difference from, allied genera, so far as it can be 

 done with the help of the hitherto discovered fossil remains. 



He then proceeds to describe all the known species of Lophiodon, 

 and begins by subdividing the genus into the five following sub- 

 genera, according to the different structure of the teeth in each sepa- 

 rate species: — 1. Coryjjhodon, Owen; 2. Tapirotherium, 'Blsimy., this 

 is the typical form to which Cuvier gave the name of Lophiodon in 

 1822, although Blainville had already named it in 1817 ; 3. Pachy- 

 nolophus, Pomel. ; 4. Lophiotherium, Gervais ; and 5. Tapirulus, 

 Gervais. 



The next subject to which the author directs his attention is the 

 examination of the Lophiodon remains of Heidenheim. This im- 

 portant discovery was made by Riitimeyer not long ago, and Dr. 

 Maack has been enabled to examine and compare about forty 

 well-preserved teeth, besides fragments of teeth, jaws, and bones. 

 These are all carefully described, and some curious anomalies in the 

 structure of the different teeth are pointed out. Thus he observes 

 that neither the molar nor premolar teeth of his new species, L. 

 rhinocerodes, would, either in form or structure, give any clue as to 

 what the canine or incisor teeth were ; on the contrary, we should 

 be greatly misled if we attempted, from the remarkable resemblance 

 between the molar teeth of Tapir and Lophiodon, to infer a similar 

 resemblance between the canine and incisor teeth of both animals. 



He then discusses the zoological position of the genus Lophiodon, 

 and shows, as a necessary consequence of recent discoveries, and of 

 which he gives Riitimeyer the chief credit, that it belongs to the 

 great family of Pachy derma ta omnivora, and concludes that Lo- 

 phiodon is not connected with Tapir and Palceotherium, although in 

 the structure of its teeth it combines many characters of these two 

 genera, but that it is more closely allied to the genera Cheer opotamus, 

 Hyopotamus, and Anthracotherium. 



With regard to the geological age of the beds in which Lophiodon 

 has been found, he comes to the conclusion, that this genus, with its 

 CO temporaries, formed a peculiar fauna, the remains of which are 

 buried in the clays, lignites, marls, freshwater conglomerates, and 

 marine limestones of the age of the calcaire grossier of Paris. The 

 work is illustrated by fourteen plates, chiefly representing the dif- 

 ferent teeth in various positions. 



I think it may be interesting to allude here to a new theory 

 respecting the transport of erratic blocks recently published by 

 Count Keyserling*. 



Finding great difficulty in accounting for many of the phenomena 

 which accompany the erratic blocks which cover the level lands of 



* Melanges physiques et chimiques tires du Bulletin de I'Acad. Imp. des 

 Sciences de S. Petersburg, tome v. 



