243 MM. Pictet and Humbert on the Fossil Fishes 



1. The fauna of Hakel has greatest resemblance to that of 

 Comen in Istria. Nevertheless it presents a greater proportion 

 of living genera, and may thus be concluded to be the more 

 recent of the two. 



2. The fauna of Sahel Alma is unquestionably related to that 

 of the Chalk of Westphalia. 



3. Both one and the other differ to a greater extent from that 

 of the Chalk of England. 



4. These differences and resemblances may be partly owing 

 to geographical causes, and partly to the respective ages of the 

 formations. The former would tend to augment the relations 

 with Comen, and to diminish those with the Chalks of more 

 northern countries, and would consequently weaken considerably 

 the importance to be attached to the resemblances. 



In spite of doubts so engendered, the precise limit to which 

 it would be impossible to lay down, our general conclusion is 

 that the faunas of the Lebanon are, both the one and the other, 

 intermediate between those of Istria and those of the Upper 

 Chalk, and that, consequently, their position is most probably in 

 the Middle Cretaceous formation. 



And here we have to deal with a question both difficult and 

 embarrassing. What is the relative age of our two Lebanon 

 faunas ? And which is the more ancient ? 



Had the labours of Botta resolved this question, and were we 

 already possessed of sufficient stratigraphical proofs, we should 

 not now be forced to have recourse to the hazard of a palseonto- 

 logical analysis, which is the more embarassing since it leads us 

 to a result quite opposed to that which the above-named author 

 somewhat prematurely regarded as probable. M. Botta be- 

 lieved the fauna of Sahel Alma to be the more ancient. The 

 comparisons which we have lately made, and which have brought 

 us to the conclusion that the fauna of Comen is more nearly re- 

 lated to that of Hakel, while that of Sahel Alma more especially 

 recalls the fauna of the White Chalk, lead us on the contrary to 

 consider the first the more ancient. It is to be hoped that a 

 complete geological survey of these countries will put an end to 

 this uncertainty. 



General Palaontological Considerations. 



The study of organic development throughout the course of 

 geological time shows that the different classes of the animal 

 kingdom are far from presenting a history uniform in this re- 

 spect. The epoch, in particular, during which the modifications 

 which have more powerfully affected the organism have taken 

 place would seem to have been by no means the same for the 



