Chap. VI.] relations of various groups. 135 



The presence of this form, Estheria, taken in connexion with the 

 occurrence of a'Labyrinthodont reptile, gives an important clue to the 

 age of the Mangali beds, and gives interest to any thread of connexion, 

 even if slight, between them and the rocks of Bengal.* But until the 

 reptilian, fossils of the Panchet group are examined, it is premature to 

 enter into any further speculations. 



The conglomerates and coarse ferruginous grits of Panchet and other 

 hills might, from their mineral character and position in the series, 

 belong to either of the groups described as ■" Mahadeva"f in Central 

 India, or in Orissai; but any such identification could only be of the 

 slightest kind on account of the distance at which these beds are known 

 to occur, mineral character being a very uncertain guide in determin- 

 ing the relations of rocks separated by so wide an interval§ unless 

 some very peculiar and marked character exists, as in the case of the 

 Talchir rocks. But in the present instance there is no distinct cha- 

 racter, beds of conglomerate and grit abound in rocks of all ages, 

 while the extension of such beds over a large area is exceptional. || 



* So far as this evidence goes, it tends to confirm Dr. Oldham's suggestions as to the 

 Damudas being Upper Palaeozoic. Por labyrinthodont reptiles, (and consequently the Panchets 

 if equivalent to the Mangalis,) being Permian or Triassic, and the Damudas being but little 

 older, would be Upper Carboniferous or Permian, or perhaps intermediate between Permian, 

 and Triassic, but the evidence is very slight. 



t Memoirs, Vol. IL, page 183. 



% Ibid, Vol. I., page 75. 



§ The beds in the Daniuda valley are about 250 miles from Talchir, those in Talchir are 

 about 350 miles from Central India. 



|| In deference to Dr. Oldham's opinion of the distinctness of the Mahadevas of Central India 

 from those of Orissa (Memoirs of Geological Survey of India, Vol. II., page 315), I have 

 treated them above as separate formations. The evidence of their identity was never very 

 strong, and the Orissa beds were referred to the " Mahadeva" group as being the only known 

 group then described to which they could be assigned. I do not think that any additional evi- 

 dence with reference to them has since been procured. It will be seen above that I do not 

 agree with Dr. Oldham's suggestion that the " Mahadevas" of Talchir and the upper grits of 

 the Raniganj field may be identical. It is by no means improbable that all three are distinct. 



