Reviews — Reyness Geology of the Aveyron, 573 



tion to the many memoirs previously published on the Aveyron dis- 

 trict, by M. de Serres (1844), PaiTan (1856), M. Boisse, and others. 

 The geological structure of the district consists of Igneous and Meta- 

 morphic rocks (porphyry, basalt, granite, and micha schist), which 

 occupy about two-thirds of the department, the sedimentary rocks 

 being only of limited extent. These latter comprise the Upper 

 Silurian, Coal-measures, Permian, Trias (with its three divisions), 

 Lias, and the Lower and Middle Jurassic strata, the drift or diluvial 

 deposits occupying the valleys. The Devonian and Carboniferous 

 limestone are wanting, and the Permian, Trias, and infra Lias are 

 unconformable to the Silurian rocks, while in the north-east of the 

 department the Upper Lias and Inferior Oolite repose transgressively 

 on the Mica schist. The Trias is well represented (112 metres), but 

 fossils are rare, gypsum occurs in the upper beds, but no rock-salt, 

 and the springs which arise from these beds are nat even saline. 

 The Avicula contoria zone, although occurring in the departments of 

 the Var and Herault, has not been strictly recognised at St. Affrique 

 (Aveyron), although some equivalent strata may exist there. The 

 Lias is marked by the characteristic zones and many fossils, and the 

 inferior Oolite, with its typical fossils, is overlain by brackish 

 water, or estuarine strata (Zone a Cyclades), containing Melania, 

 Paludina, Cyclas, Mytilus, TJnio, associated with carbonaceous shales, 

 imperfect coal, and Oolitic iron ores, or limonite ; these strata have 

 been described by Marcel de Serres (Bull, de la Soc. Geol. de France, 

 vol. xvi., p. 99), and appear to represent the Moorland Coal series of 

 the Oolitic strata of Yorkshire ; they are covered by beds of the 

 Oxfordian series. 



Six plates of fossils and one of sections are appended to this 

 memoir, as well as the description of the new species, sor»e of which 

 we are rather inclined to consider require further comparison. 



III. — Eevue de Geologie pour les annees 1865 et 1866, par M. 

 Delesse et M. de Lapparent. Paris, 1868. 



IlHE fifth volume of this annual is of equal importance, usefulness, 

 and interest to those of previous years, and contains a resume of 

 the more important geological works published during 1865, arranged 

 under four heads. Preliminary, Kocks, Formations, and Geological 

 descriptions. 



IV. — Catalogues des Poissons des Formations Secondaires du 

 BouLONNAis, par M. Emile Sauvage. Boulogne, 1867. 



THE Museum of Boulogne contains a fine collection of fossil 

 fishes, chiefly from the Jurassic strata of the Boulonnais, as 

 well as some from the Devonian and others from the Cretaceous 

 rocks of the district, of which the above work is a catalogue, con- 

 taining also description and four plates illustrating some of the 

 species. From this catalogue, it appears that the ichthyic fauna of the 

 Bathonien or Great Oolite consists mostly of Pycnodonts -dud Cestracionts 

 in about equal numbers, and two Lepidoids, one of which, the Lepi- 



