38 



THE GEOLOGIST. 



Zoological, Geological, and Geologico-geographical considera- 

 tions on the Ammonites of the Cretaceous period; translated 

 from the " Paleontologie Franqaise,'' of A, d'Orbigny, 

 Communicated by T, Johnson, Esq. 



The study of fossil organic remains is frequently confined 

 to imperfect descriptions of species, without entering into 

 enlarged zoological or geological views on the subject; and 

 these descriptions, often incorrect, served notwithstanding 

 as a base for geological applications, which, on that account, 

 might not only perpetuate errors, but might also induce 

 geologists to attach to them less importance than they really 

 deserved. The ammonites were especially in this condition, 

 and the genus was in an inextricable state of confusion, not- 

 withstanding the figures of Sowerby* and the monograph of 

 M. de Haan,t when Leopold von Buch recognized in these 

 organized bodies, the internal important characters, which 

 had until then been neglected, but which he considered might 

 be usefully applied to the determination of the species. In 

 three successive memoirs,]; this illustrious naturahst occupied 



Sandon Bury, Herts, and in whose possession they now are. These 

 remains consist of two perfect horns, and a part of the skull of a large 

 animal belonging to the Genus Bos j the horns are 27i inches long, and 

 measure 1 5 inches in circumference at the place they are inserted in the 

 skull. At the same time were found portions of the antlers of the Rein- 

 deer. The whole of these specimens were discovered at one spot, and in 

 the chalk, a few feet below the surface. They do not appear, however, 

 to have been actually imbedded in the chalk strata, but to have fallen 

 into a large fissure or rent, which was subsequently filled up. — Ed. Geo- 

 logist. 



* Mineral Conchology of Great Britain, 

 t Monographise Ammoniteorum, 1825. 



X Annales des Sciences Naturelles, 1829, tome 17, p. 267. Loc. cit. 

 tome IS, }). 417, et tome 19-. p. 5. 



