456 Geological Society : — Anniversary of 1839. 



by any traveller, -which rises abruptly from tlie alluvial plain of 

 Caesarea to the height of 13,000 feet. 



We have another contribution to the geology of the countries 

 exterior to the Alps and Pyrenees in Mr. Sharpe's memoir on the 

 geology of Portugal. He has examined with great care the neigh- 

 bourhood of Lisbon, and lias traced the superposition of tlie strata, 

 naming the most conspicuous of them from the places in which 

 they are well exhibited. His series (exclusive of igneous rocks) 

 consists of San Pedro limestone (which rests upon the granite), 

 slate clay and shale, Espichel limestone, voA sandstone, hippurite 

 limestone, a lower tertiary conglomerate, the Almada beds, and the 

 upper tertiary sand. In the Memoirs of the Royal Academy of 

 Sciences of Lisbon, for 1831, Baron Eschwege had examined a 

 geological section taken across the mouth of the Tagus, and passing 

 from the granite of the Serra of Cintra, to that of the Serra of Arra- 

 bida. But his identifications of the Portuguese beds do not agree 

 with those of Mr. Sharpe, and have indeed the air of proceeding on 

 the arbitrary assumption of a correspondence between this and 

 other parts of Europe. Thus Baron Eschwege has referred both 

 the San Pedro and the Espichel limestones to the magnesian 

 limestone ; the red sandstone formation he considers as Bunter 

 Sandstein, while Mr. Sharpe refers it to the age of our Oolites : the 

 hippurite limestone (now acknowledged to be the equivalent of our 

 chalk and greensand) M. Eschwege makes to be Jura limestone ; and 

 the Almada beds he would have to be Plastic Clay and Calcaire 

 Grossier. Mr. Sharpe is ^'ery properly attempting, by a further 

 study of the organic fossils which he has procui'ed, to confirm or 

 correct tlie identifications to which he has been led. It is only by 

 thus starting from different points, and tracing strata by their conti- 

 nuity, that we can hope to cover the map of Europe, and finally 

 the world, with geological symbols of a meaning fully understood. 



PALAEONTOLOGY. 



The portion of our subject which we term Palaeontology, might 

 at first sight seem to form a part of zoology rather than of geology ; 

 since it is concerned about the forms and anatomy of animals, and 

 differs from the usual studies of the zoologist only in seeking its 

 materials in the strata of the earth's crust instead of upon its sur- 

 face. Yet a moment's thought shows us how essential a part of 

 our science the zoology of extinct animals is ; for in order to learn 

 the history of the revolutions which the earth has undergone, we 

 must seek for general laws of succession in the remains of organic 

 life which it presents, as well as in the position and structure 

 of its brute masses. And since such general laws must necessarily 

 be expressed in terms of zoology, it becomes our business to define 

 those terms, so that they shall be capable of expressing truths which 

 include in their circuit the past as well as the present animal and 

 vegetable population of the world. 



An example of this process has occupied a large portion of our 

 attention during the past year. It appeared to be a proposition 



