94 



THE GEOLOGIST. 



The summary of the arrangement is as follows : viz.: — 



Rudista. r Hippurites. r H. bioculata. Lam. 



I % H. canaliculata, Roquan. 



I J H. striata. Def. 



J H. sulcata. Def. 



I i turgida. Roquan. 



I ^ H. organisans. Montf. 



v. Spherulites. S. ventricosa. Roquan. 



Having arrived therefore at the sum and substance of this 

 work, and devoted some space to the arguments deduced by 

 the author in support of his views, we will, in conclusion 

 offer a few remarks as to the merits of his investigation, 

 displaying a vast amount of perseverance and knowledge, 

 and as to the conclusions at which he has arrived with refe- 

 rence to the classification of individuals occurring in this de- 

 posit. Our author evidently observed prototypes of La- 

 marck^s species in the strata of Corbieres, and it was on the 

 score of his opinions only, that he hesitated to assign a place 

 to those, which, possessing apparently the same specific dis- 

 tinctions, might have been severally referred to Lamarck^s 

 divisions ; yet the minutiee of structural differences are 

 often so confounded that, by insensible gradations, ti'ue 

 species become connected together and emerge into one 

 general type; and the natural system of arrangement, as 

 recognized in modern times, however averse in principle to 

 the introduction of new species without sufficient authority 

 or reasons, is, on the contrary equally subservient to the 

 adoption of an infinitude of gradations, connecting the one 

 specific form with the next ; and reasoning by analogy also, 

 it is obvious that no fixed limits can be assigned to the ope- 

 rations of nature. We could not, however, attempt to de- 

 cide on the particular merits of this case, yet we should he- 

 sitate to give our assent to the reduction of species espe- 

 cially when we consider the multiplicity of individuals which 

 came under the author^s observation, without great care 

 and caution. 



