Dr. Walter Flight — History of Meteorites. 311 



Orbitoliles has been found by Giimbel (see the Geological Magazine, 

 Vol. X. p. 82). 



The Foraminiferal faunas of the Rhastic and the Trias, as far as 

 known, are very similar to the Jurassic. See the Geological 

 Magazine, Vol. VII. p. 180. 



V. — A Chapter in the History oe Meteorites. 

 By Walter Flight, D.Sc, F.G.S. 



Of the Department of Mineralogy, British Museum ; 



Assistant Examiner in Chemistry, University of London. 



(PLATE IX.) 



(Continued from page 267.) 



1776. — Krasnoyarsk, Siberia. (The Pallas Iron.) 1 



This celebrated siderolite has recently been sawn into two nearly 

 equal parts, and the occasion presented a fitting opportunity for an 

 exhaustive examination of its constituent minerals, more especially 

 of the olivine forming the chief ingredient. It was accordingly 

 undertaken by von Kokscharow, at the desire of the Imperial 

 Academy of Sciences, and his memoir is mainly devoted to a de- 

 scription of the crystallographic characters of the silicate enclosed 

 in the nickel-iron. 



He finds that the interior presents no new leading features. The 

 olivine, which has a greater number of crystal-faces than Pallas ob- 

 served on it, occurs not only in spherular or drop-like masses bearing 

 numerous faces, but in tolerably well-developed crystals, which, 

 though rounded here and there, exhibit sharp edges, and a consider- 

 able number of forms, some of which have not been observed on 

 terrestrial olivine. The individual crystal has generally a rounded 

 surface, on which the planes lie ; and although these are separated 

 from each other by curved areas, their mutual inclination enables 

 the observer to identify them. They are in most instances smooth 

 and lustrous, and allow of the most accurate goniometrical measure- 

 ment being performed. The best developed faces are : c = oP; 

 d = P oo ; and o = |P. Biot 2 showed half a century since that 

 these rounded masses of olivine exhibit crystalline structure, and 

 possess two optic axes. The first minute investigation of them 

 was conducted by G. Rose. 3 



Eose observed eleven crystal-forms on the Pallas olivine ; von 

 Kokscharow has added eight more, making nineteen altogether, 

 which are as follow : 



1 N. von Kokscharow. Bull. V Acad. Imp. 8c. St.-Petersbowg, 1870, xx., No. 3. 

 Memoires V Acad. Imp. Sc. St.-Petersbourg, xv., No. 6 Jahrb. Mineralogie, 1870, 

 778. — E. BL von Baumhauer. Archives Neerlandaises, 1871, vi. — G. von Helmer- 

 sen. Zeitsch. Deutsch. Geol. Gcsell. xxv., 347. 



2 J. B. Biot. Bull, de la Soc. Philomatique, 1820, 89. 



3 G. Eose. Fogg. Ann., 1825, iv., 186. 



