152 On (he Zciiglodon. 



Tn the eveiiino- iNIr Hodge made a few remarks on the economical 

 o-eolooy of Berkshiie. 



MrCesor read a report on the Drift of New England. As the 

 views were mainly those offered by this gentleman a few days since, 

 \vhen a kindred subject was under discussion, and as we then made 

 a brief abstract of the same, we shall make no report of the remarks 

 presented by him on Friday evening. M. Desor sustains the glacial 

 theory. 



Remarks were made on the subject of M. Desor's report by Pro- 

 fessors H. D. Rogers and Agassiz. Professor Rogers also made a 

 leport on the Drift of New England. He differs from M. Desor in 

 his views of the same. Professor Rogers is an advocate of the 

 diluvial theory. 



0)1 the Zeuijlodon — Koch's Hi/drarchos. 

 The recent publication of a report by Carus of Dresden, on 

 these interesting remains, has again called attention to the 

 controversy with regard to their true nature. The main 

 points in dispute are two : — 



I. As to the fact of the bones belonging to one and the 

 same individual. 



II. As to the nature of the animal, whether a Reptile or a 

 Mammal. 



I. Mr Koch avowed that the bones all belonged to one 

 and the ^ame individual — that they were found in one loca- 

 lity, and very nearly in their natural order. Dr Gescheidt 

 of New Yoi'k, after examining the skeleton, maintained that 

 this statement was correct, as is obvious fi'om the following 

 paragraph — 



" Having by this, as shortly as possible, proved that the 

 A-ertebral column of the Hydrarchos is not composed of dif- 

 ferent vertebra^, but is a whole and an integral part of a 

 fossil animal, &c." 



Carus of Dresden, relying upon Koch's statement, enter- 

 tains the same view. 



On the other hand, it was denied that the vertebral column 

 above mentioned did belong to one and the same individual, 

 because the bones of which it was made up presented dif- 

 ferent degrees of ossification, some of the bones being in a 

 mature, and others in an immature, condition ; a state of 

 things never occurring in one and the same animal. 



