ESTHERIA KOTAHENSIS. 81 



Thus divided as the opinions of the Indian geologists are respecting the age of these 

 plant-bearing and Estherian strata of Central India, I venture still to regard them as 

 belonging to the ' Rhsetic Formation,' in accordance with some suggestions which I made 

 in 1856 (' Quart. Journ. Geol. Soc.,' vol. xii,p. 376). 



Habitat. — The absence of marine-remains in the Plant-bearing and Reptiliferous sand- 

 stone of Mangali goes far to indicate the freshwater habitat of the Estheria so abundant 

 in one of its beds. 



Dr. T. Oldham, F.R.S., the Superintendent of the Geological Survey of India, has 

 kindly and promptly. forwarded to me a piece of the Estheria-bed not long since dis- 

 covered by Mr. W. T. Blanford, near Panchet (pronounced Pa'cheet), five miles south 

 of the Damuda River, and 110 miles north-west of Calcutta, in Bengal. (See 

 'Memoirs Geol. Survey, India,' vol. hi, part 1, pp. 132 — 137, and p. 197 ; also 'Journ. 

 Bombay, Asiat. Soc.,' vol. vi, p. 203.) The rock is a fine-grained, yellowish-grey, sandy, 

 micaceous shale. The Estheria are of small size, lie closely together on one plane, and, 

 retaining no shell, or only an excessively fine film, are represented by obscure casts and 

 moulds, of a darker tint than the matrix. A few fragmentary plant-remains lie on the 

 same bed-plane. 



The general size of the specimens is as follows — 



Height ^ inch; Length ^i-inch; Proportion 1 : lf + 



In shape the valves appear to be subovate, with a tendency to become oblong (like 

 fig. 21, in PL II). The concentric ridges are delicate and apparently numerous 

 (about 20) ; but no ornament of the interspaces can be discerned even on the few valves 

 that retain a film of shelly matter. 



Altogether, judging from the materials before me, I have no grounds for deciding 

 whether this Estheria from Panchet is or is not the same as that from Mangali, some of 

 the smaller forms of which it seems to resemble, as already suggested by Hislop and 

 Oldham ('Journ. Bombay Asiat. Soc.,' vol. vi, p. 203). 



8. Estheria Kotahensis, Spec. Nov. PI. II, figs. 24,25. 



Estheria, Hislop. Quart. Journ. Geol. Soc, vol. xvii, p. 348. ; Journ. Bombay Asiat. Soc, vol. 

 vi, p. 201. 



Height, more than \i inch") 



\ ^Proportion 1 to l^-f 

 Lensth 44 ., ' 



Length 



Estheria have been found by the Rev. Mr. Hislop in a light-coloured shale at Kota 



11 



