58 HOLLAND AND TIPPER : INDIAN GEOLOGICAL TERMINOLOGY. 



the island of Bombay. Here, again, the fauna, is freshwater 

 containing numerous skeletons of frogs, described by Stoliezka 

 as belonging to the genus Oxyglossus, a tortoise and an entomos- 

 tracous crustacean (Cypris). There can be very little doubt that 

 the intertrappeans as a whole are Cretaceous, and this is very 

 greatly strengthened by the occurrence of Physa prins&pii in the 

 Meestrichtian of Baluchistan (E. Vredenburg, Rec. Geol. Surv. hid., 

 XXXV, 114, 1907). 



Irlakonda quartzites.— The lowest beds in the Kistna series of the 

 Cuddapah system, named by W. King (Mem. Geol. Surv. Ind., 

 VIII, 255, 1872) from the hill (16° 2' ; 78° 41') which is formed of 

 these rocks, in the Kurnool district. 



Iron Clay. — Dr. H. W. Voysey's name for laterite. See Journ, As. 

 Soc, Beng., II, 302, (1833) ; XIX, 190, (1850). The term 

 did not, however, oust the older term laterite ; but in 1876 it was 

 revived by B. Bruce Foote [Mem. Geol. Surv. Ind., XII, p. 200) 

 for the high-level laterite of the Ghats in the Southern Mahratta 

 Country, whilst he restricted the term laterite to the low-level 

 variety of the Konkan. But the term has again fallen into disuse. 



Ironstone Shales. — Term retained for the stage of the Damudas 

 intermediate between the Lower Damudas (Barakars) and the 

 Baniganj stage (W. T. Blanford, Mem. Geol. Surv. Ind.. Ill, 28, 

 1861). Worked for the clay-ironstone nodules in the neighbour- 

 hood of Barakar. They are found also in the Jherria field where 

 the shales are comparatively poor in clay-ironstone. 



Irrawaddy system.— Name adopted by F. Noetling {Rec. Geol. Surv. 

 Ind., XXVIII, 76, 1895) roughly to correspond in Burma to the 

 " Fossil-wood group " of W. Theobald (Rec. Geol, Surv. Ind., II, 

 79, 1869 ; Mem. Geol. Surv. Ind., X, 247, 1873). In 1869 

 Theobald regarded the age of the beds as probably Miocene, but 

 inclined in 1873 to the arguments of W. T. Blanford (Journ. As. 

 Soc. Beng., XXXI, 225) in favour of a younger age, which he gave 

 as Pliocene to " Post-Pliocene." Noetling (Rec, XXVIII, 76) 

 included in the Irrawaddy system " all beds above the Yenan- 

 gyaung stage which are characterised by the remains of terrestrial 

 and fluviatile animals, but below the unconformity which separates 

 the post-tertiary from those of tertiary age." M. Stuart, from 

 evidence collected in Western Prorne (Rec. Geol. Surv. Ind., 

 XXXVIII, 271, 1910), concluded that the Irrawaddy system in 

 that area should be extended down to include marine beds which 



