90 HOLLAND AND TIPPER : INDIAN GEOLOGICAL TERMINOLOGY. 



literature see 0. Diener, Mem., Geol. Surv., ltd., XXXVI, 18-20 

 and 45, 1912. 



O'Rileyite —Name given to a mineral from Burma by Dr. D. Waldie 

 (Pwc, As. Soc. Bencj., 1870, 279) after Mr. 6'Riley, Deputy 

 Commissioner of Martaban, and composed of copper, iron, arsenic 

 and antimony. No formula was assigned to it. A recalculation 

 of his results by F. R. Mallet (Man. Geol. Ind., Pt. IV, 1st Ed. 

 Mineralogy, 1883, 15) shows it to be a mineral allied to domeykite. 

 The exact locality in the Tenasserim division is unknown. 



OtoceraS beds. — The name Otoceras was given by C. L. Griesbach 

 to a new genus of Ammonites found by him in the Central Hima- 

 laya of Eumaon (Rec, Geol. Surv., Ind., XIII, 105, 1880) in beds 

 which he correlated with the Campil or Upper Werfen beds of 

 Europe. These beds were included in the Triassic system, but were 

 regarded as passage beds in a conformable sequence from Per- 

 mian to Trias (Rec, Geol. Surv., Ind., XXIII, 165, 1889 ; Mem., 

 Geol. Surv., Ind., XXIII, 68, et seq., 1891). W. Waagen {Pal. 

 Ind., XIII, Part IV, 215, 232, 1891) correlated the beds contain- 

 ing Otoceras with those of Djulfa, regarding them as transitional 

 between the Palaeozoic and Mesozoic, but on the Palaeozoic 

 (Permian) side of the boundary. E. v. Mojsisovics (Sitzungs. 

 Jcais. Ahad. Wien, CI, Part 1, 377, 1892) considered the fauna 

 to be distinctly Triassic, pointing out that the Otoceras of the 

 Djulfa beds represented a lower stage in the development of 

 the genus. C. Diener (Pal. Ind., Ser. XV, Vol. II, pt. 1, 168- 

 172, 1897 ; Ibid., XV, Vol. VI, Mem. No. 1, 169, 1909 ; Central- 

 blatt f. Min. 1900, 1 ; 1901, 513, 655 ; 1905, 1 ; Mem., Geol. Surv., 

 hid., XXXVI, 42, 1912) gives evidence in favour of regarding 

 the Otoceras beds as Triassic, in opposition to the views of A. 

 v. Krafft (Centralblatt f. Min., 1901, 275) and F. Noetling (Cen- 

 tralblatt f. Min. 1900, 216 ; Neues Jahrb. f. Min., Beilagebd., 

 XIV, 467 ; Lethaea Palseozoica, II, 656, 1901, Neues Jahrb. f. Min., 

 XVIII, Beilage Bd., 546, 552), who regarded the beds as Permian. 

 A. Bittner corroborated Diener's views by an examination of the 

 lamellibranch fossils (Pal. Ind., Ser. XV, Vol. Ill, Part 2, 74, 

 1899), and a full discussion of the case is given by Diener in Mem., 

 Geol. Surv., Ind., XXXVI, Part 3, 42-55, where new evidence 

 is given to show that the Otoceras beds are equivalent to the 

 lowest division of the Werfen (Lower Seis) beds. The boundary 

 of the Permian and Trias would thus be drawn between the 



