522 HEKRY P. BLANFOBD ON THE 



sandstones, which in South Rewah attain to a great thickness. The 

 reports and maps of this field have not yet been published ; but the 

 rocks occurring in the Mahanadi valley, at its north-western extre- 

 mity, have been briefly described in Mr. J. G. Medlicott' s Eeport on 

 the central portion of the Nerbudda district*. In this valley and 

 that of the Johilla, two groups of rocks, in addition to those above 

 noticed, appear, termed the Lameta and Jabalpurf groups, only 

 the lower of which is included in the plant-bearing series. It con- 

 tains the remains of Cycads and Coniferous plants, some of which 

 have been identified with those of the Rajmahal group. Dr. Oldham 

 considers that it represents in the JSTerbudda district the lower por- 

 tion of the Rajmahal group J. 



III. In the Satpura field, lately described by Mr. H. B. Medlicott§, 

 the plant-bearing series attains an enormous thickness. The Talchir 

 and Barakar beds appear at the base ; but the overlying groups are 

 only doubtfully to be identified with those of Western Bengal. The 

 following is their succession, in descending order, with their respec- 

 tive thicknesses, as given by Mr. Medlicott : — 



1. Jabalpur group 500 or 600 feet. 



2. Bagra group 1 f 800 „ • 



3. Denwa group I Mahadeva series < 1200 „ 



4. Pachinari group... J (8000 „ 



5. Almod and Bijori group 3000 to 4000 „ 



6. Motur group ? 



7. Barakar group 400 or 500 „ 



8. Talchir group ? 



The maximum aggregate thickness of these beds is therefore upwards 

 of 15,000 feet. Group 5 is considered by Mr. Medlicott to represent 

 the Panchet and Raniganj groups of Bengal [and perhaps the Kamthis 

 and Panchets of the Godavery valley]. In the Bijori, or lower part 

 of this group, were found the remains of. an Archegosaurus ||, the only 

 fossil of animal origin hitherto met with in the whole of this enor- 

 mous series. Imperfect plant-remains also occur in the same group. 



IV. Passing to the Nagpore country and the Godavery valley, the 

 character of the series again alters. The Talchir and Barakar groups 

 are still constant at the base of the series ; and on them rest a 

 group of rocks well developed all through the area, viz. the " lami- 

 nated sandstones" of Mr. Hislop^f, the Kamthi group of the Geo- 

 logical Survey**. Unfortunately the valleys of the Godavery and its 

 tributaries, the Pranhita, the Pain Gunga, the "Wain Gunga, and the 

 Wardha, in which the plant-bearing series occur, are much covered 

 by later Tertiary and recent alluvial deposits ; so that the visible 

 sections are few and small, and the thickness of the groups has not 

 been ascertained. 



* Mem. G. S. I. vol. ii. p. 176. 



t Originally termed Upper Damuda ; but this name, being based on an erroneous 

 assumption, has been abandoned. 



\ Mem. a. S. I. yoI. ii. p. 325. § Ibid. vol. x. Art. 2. 



|| Op. cit. vol. x. Art. 2, p. 27. 



1 Quart. Journ. Geol. Soc. 1855, vol. xi. pp. 370, 373. 

 ** Mem. a. S. I. vol. ix. Art. 2, p. 6. 



