AMMONITES — ZOOLOGICAL^ ETC. 



309 



subject, ere he first divulged his theory ; or, now that he 

 has divulged it, he should not hesitate to correct any erro- 

 neous impressions to which his opinions have given rise ; 

 for, in our opinion, every new observation or discovery made 

 by him, tends simply to prove a comparatively insignificant 

 scene of action ; although even its present effects in the 

 abrasion and transportation of blocks of stone are very con- 

 siderable. We are afraid that the real scientific character 

 of the " glacial expedition " is lost ; for we find with these 

 scanty results before the public, there is much lecturing at 

 the summit of the Aar, and the table d'hote at the Hotel 

 des Neufchatelois is by no means despicable — far different 

 from the " scientific" fare of liugi in his previous ascents. 



We shall look anxiously for further results from this ex- 

 pedition, but fear very greatly that we are doomed to be 

 disappointed, from the accounts which we have received 

 from our friends. 



The Editor. 



Ammonites Zoologically and Geologically considered, 



(Continued from p. 281.) 



Division of the Ammonites in the separate groups. 

 Having defined the three groups of the Cretaceous for- 

 mations, an inquiry as to the number of species of Ammo- 

 nites which have existed at each epoch, gives the following 

 results : 



Neocomien period , . . 75 species, 

 Gault e .... 42 J, 

 Chalk ..... 27 „ 

 Thus, without noticing forms, I find that the species of 

 Ammonites which are so numerous in the Jurassic forma- 

 tion, are in the Cretaceous formation : 1 st. at the maximum 

 Qi their numerical development, in the Neocomien formations; 



Y 2 



