526 HENRY F. BLANEORD ON THE 



mind that we have to deal with a series of deposits of very con- 

 siderable aggregate thickness. It has been shown that in the 

 Damuda fields, omitting the upper sandstones, which both litholo- 

 gically and by their position would seem to represent some part of 

 the Mahadeva series, we have a thickness of 10,700 feet ; and in 

 the Satptira field, omitting the groups five to eight, which are pro- 

 bable equivalents of the former, we have an equal thickness (10,600 

 feet), making a total maximum of 21,300 feet of deposits, in which 

 are several interruptions (evidenced by unconformity), though not 

 perhaps of any great amount. There is certainly, then, no need, on 

 stratigraphical grounds, to compress the plant-bearing series into 

 very narrow limits of time ; and we must be careful not to confuse 

 the fossil evidence, such as it is, that is afforded by the different 

 groups. 



The Panchet and Eaniganj groups with the Kamthi group, which 

 we may assume provisionally to be of intermediate age to the two 

 former, are those the fossil evidence of which is the least imperfect. 

 Following Mr. Medlicott, I shall regard the Bijori group as the local 

 equivalent of the Eaniganj -beds of Bengal, though it may perhaps 

 with equal probability be regarded as the equivalent of the Kamthi 

 rocks. 



The Bijori and Eaniganj -beds together have furnished the Carbo- 

 niferous genus Archegosaurus and plant-remains which, when com- 

 pared with those of European formations, admittedly throw very 

 little light on the question of age. The Kamthi group has yielded 

 a Labyrinth odont not nearly allied to any European form, an 

 Estheria, and plant-remains in part identical with those of the 

 Eaniganj -beds. The Panchet group has furnished Hyperodapedon 

 and Ceratodus, both genera of Triassic affinities ; also two new 

 genera of Labyrinthodonts, a Dlcynodon, and a fragment of a 

 Thecodont saurian. "With respect to these last, Professor Huxley 

 remarks, " at present I think there is no evidence to decide whether 

 they are older Mesozoic or newer Palaeozoic ;" and in another paper 

 on Hyperodapedon he guardedly observes, " even now that Hypero- 

 dapedon is distinctly determined to be a Triassic genus, the possi- 

 bility that it may hereafter be discovered in Permian, Carboniferous, 

 and even older rocks remains an open question in my mind. Con- 

 siderations of this kind should have their just weight when we 

 attempt to form a judgment respecting the Eeptiliferous strata of 

 the Karoo formation in South Africa, and of Maledi and elsewhere 

 iu India." Perhaps the same caution, with an opposite tendency, 

 may be observed with respect to the evidence afforded by Arche- 

 gosaurus. 



The evidence of age, then, afforded by a comparison of the fossil con- 

 tents of these formations with those of European rocks leads only to 

 somewhat vague conclusions. It indicates little more than that these 

 formations probably range somewhere between the Carboniferous 

 horizon and that of the Trias. The occurrence of Archegosaurus 

 would tend to depress the Bijori and, with it the Eaniganj group to a 

 Carboniferous horizon, and that of Hyperodapedon and Ceratodus to 



