Br'iart and Cornet — " Meule" of Bracquegnies. 311 



of the country, inasmuch as the latter possess a peculiar superficial 

 alteration, accompanied with traces of oxide of iron, which bespeak 

 their antiquity. The implements are made from the black flints of 

 the chalk. H. B. W. 



V. MiNERALOGICAL, GEOLOGICAL, AND PaL^ONTOLOGICAL AcCOTJNT 



OF THE " MeULE " (GtRINDSTONe) OF BkAOQUEGNIES. 



By MM. Bbiart and Cornet, Civil Engineers. 



THE rock, to which the miners of the neighbourhood of Mons 

 have given the name Meule, is one of the most interesting of 

 the Cretaceous strata of Hainaut. It is a glauconitic and opaliferous 

 sandstone, attaining sometimes 180 metres in thickness. The hy- 

 drated and soluble silica, which it yields abundantly, distinguishes it 

 from all the other Cretaceous rocks. It is placed by Dumont in the 

 upper part of his Hervien system, and is therefore the equivalent of 

 the Gault. Few fossils have hitherto been obtained from it, but the 

 authors now record, from two well-borings at Bracquegnies, 93 

 species, namely : — 41 Gasteropods, 51 Lamellibranchs, and 1 Ser- 

 pula. There is a remarkable absence of Brachiopods and Cephalo- 

 pods, and this fact, together with the mineralogical character of the 

 rock, (?) point to its formation in deep water, and at a considerable 

 distance from the land. 



Fifty-one of the species noticed are well-known forms, and afford 

 material for the comparison of the Meule bed with other deposits 

 5 of these species are found only in the Tourtia of Tournay and 

 Montignies-sux-Eoc ; 8 in the Cenomanian strata of Kouen ; 13 in 

 that of Sarthe ; and 42 in the Blackdown Beds. 



The memoir is illustrated mth seven quarto plates of the fossils, 

 drawn by M. Briart, and accompanied with carefully prepared de- 

 scriptions. — L'Institut, May 16, 1866. 



VI. — ^Trans-Caucasian Eesearches by H. Abioh. 



[Apercu de mes Voyages an Transcatjcasie en 1864. Par H. Abich. 8vo. 



Moscow, 1865.] 



N communicating to the Imperial Academy at Moscow the results 

 of his travels in 1864, in the regions south of the Caucasus, M. 

 Abich mentioned that the points he had in view during his last five 

 excursions from Tiflis were chiefly to define the limits and characters 

 of the Tertiary and Secondary Strata of the Southern flanks of 

 the Caucasus, — to study the relationships of the schistose and 

 granitic rocks of the chain, and the trachytes of the extinct volcanos, 

 Elbourouz and Kasbek ; also to examine the Tertiary and Quartemary 

 formations of the plain of Colchis, and to finish his special geological 

 map of the canton of Sazeretlo. As a point of geological interest 

 and of practical importance, M. Abich refers to the great extent of 

 the Oxfordian Kocks in the mountains between the Kour and the 



