SUPPLEMENT FOR 1874. 407 



Hyatt, A. Evolution of the Arietidae [group of Ammonites]. 

 Froc.^ Boston Nat. Hist. Soc. vol. xvi. pp. 166-170. 



Issel, Prof. A. Geologia e paleontologia, Istruzioni seientifiche pei 

 viaggiatori. [Geological part of Scientific Instructions for Tra- 

 vellers.] Riuista Marittima. 



Itier, Jules. Des Forets Petrifiees de I'Egypte et de la Libje, et du 

 role qu'ont joue les Eaux Minerales dans les Formations Geologiques 

 posterieures aux Depots des Terrains Tertiaires. [The Petrified 

 Forests of Egypt and Libya, and the Part played by Mineral Waters 

 in post-Tertiary Times.] Pp. 16. 8vo. Montjpellier, 



. Des Brcches Osseuses des cotes des environs de Marseille. 



Pp. 5. [Annexed to the foregoing.] 



Jenkinson, H. T. Practical Guide to the Isle of Man. 8vo. London. 



Mineralogy by B, M. Wright, pp. 217-238, with a descriptive list 

 of the minerals of the island, and a list of the metalliferous mines. 

 GEOLottr, pp. 239-248. W. W. 



Jolinson, M. H. The Nature and Formation of Flint and allied 

 bodies. Pp. 16, with plate. 8vo. London. 



Maintains that flint is an organic structure in which silica has at 

 some stage of the decomposition replaced its isomorph carbonic anhy- 

 dride. The siliceous structure thus produced has been altered by infil- 

 tration of dissolved silica, which may have crystallized in its interior. 

 By the action of acids on thin sections, the writer has revealed the 

 existence of organic structure in Septaria from the London Clay and 

 Kimeridge Clay, in ironstone from the Woolwich Beds, in flints and iron- 

 pyrites from the Chalk, in phosphatic nodules from the Gault, in the 

 Cambridge phosphatic nodules, in clay-ironstone from the Coal Measures, 

 and probably in the small round grains in oolitic rocks. Also remarks 

 on the production of orbicular silica. F. W. R. 



Karpinski, A. [The Geological Constitution of the Ural Mountains, 



near Orenburg.] Gornoi Journ. vol. ii. pp. 288-314, geol. map, 



1 pi. (sections), 5 figs, in text. 



These mountains are composed of newer Silurian, Devonian, Mountain 



Limestone, and Sandstones. The map extends from the Ural River to 



the Bilaia Kieka. A. B. 



[The Composition of some Igneous Bocks.] Gornoi Journ. 



vol. iii. pp. 46-60. 



Kneeland, S. [On the Geology of the Pacific Railroad.] Proc. 

 Boston hoc. Nat. Hist. vol. xvi. pp. 375, 376. [Abstract.] 



Kokscharow, N. v. Notiz uber Perowskit-Krystalle. [Perowskite 

 Crystals.] Bull. Ac. Imp. Sci. St. Petershourg, t. xx. pp. 276-292, 

 5 woodcuts. 



Goniomotrical measurements of specimens from the Ural 



