﻿1850.] CATULLO ON THE RED AMMONITIC LIMESTONE. 



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under the persuasion, that there is a difference of opinion existing as 

 regards the situation I have assigned to the red ammonitic limestone ; 

 whereas having gone over the old classification of the cretaceous 

 system which I proposed in my work on Fossil Zoology, published in 

 1827, 1 find now that I perfectly agree with the great proportion of 

 geologists. Nor, in doing so, do I find that I contradict any of the 

 deductions I have been able to gather from the observations I have 

 already published in my other works ; for besides having always 

 attended to the facts offered to me by palaeontology, even when they ' 

 disagreed with the classification of formations I had adopted*, I took 

 especial care to direct my attention to the species that are most con- 

 stantly found, and in the greatest abundance, within the limits of a 

 given formation, and to attribute to them their due value. I say 

 the greatest number of individuals, because it sometimes happens 

 that a few are met with out of their usual position, and mixed up 

 with individuals of species more or less ancient than the deposit to 

 which the former belong. This fact was first announced by the elder 

 Brongniartf, and has been mentioned by many other geologists % ; 

 it is well known what discussions were occasioned at a meeting of 

 the Geological Society of France, by Fitton's discovery that that 

 Ammonites Deshayesii, Leym., which abounds in the inferior chalk 

 of the Caucasus, and other fossil species belonging to the gault, are 

 found likewise in the neocomian limestone of England (meeting of 

 the 21st May, 1844). This is the case with the Ammonites fascicu- 

 laris, D'Orbigny, and with a few other cretaceous species which I 

 found in that division of the red ammonitic limestone, which I now 

 propose to distinguish by a new name, as I shall presently show. It 

 is sufficient to glance over the history of the palseontological observa- 

 tions that have been made during the last few years, to learn that 

 the mixture of ancient fossils (not only the remains of animals but 

 those of plants) with those of more modern formations is a fact that 

 does not admit of dispute. The rocks of the Permian period, as you 

 well know, contain different florae ; that is to say, they may be found 

 in several formations, and the flora of the Keuper is so distinct from 

 the flora of the Gres bigarre, as not to present any palseontological 

 analogy with the other divisions of the Trias, with which it has been 

 associated §. As regards the few species of Ammonites which I persist 

 in considering as common to many formations, I must beg you, Sir, to 

 consider that a course of thirty-eight years of observation, and that 

 too in places not yet examined by any other geologist, ought to in- 

 spire more confidence than can be placed in one who, wanting this 

 requisite, supports the contrary. The red limestones occupy a great 

 extent of country, and belong partly to the jurassic system and partly 

 to the cretaceous. In the first case, when they belong to the jurassic 

 system, they constitute a most important group of rocks, distinguished 

 by the epithet of [Sopra-jurassico] upper-jurassic [?] ; because, in 



* Zoologia Fossile, p. 263, Padua, 1827, 4to. 

 f Annales des Mines, 1821. 

 X Societe Geologique de France, 18 Juin, 1843. 

 § Institut, Oct. 1849. 



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