82 FOSSIL ESTHERItE. 



(or Kotah), on the Pranhita, together with ganoid Fishes {Lepidotus Deccanensis), Cyprida^ 

 Insects, TJnio (?) and some Plant-remains. 



These JEstheria occur as very thin, light-brown, compressed, and often ragged carapace- 

 valves, in a whitish calcareous shale, , thickly crowded on the thin laminae, and associated 

 with a layer of Cypridce (see Appendix, PI. V, fig. 25), and minute, straight, black, fibrous 

 lines, probably of vegetable origin, lying horizontally in every direction throughout the 

 shale. Small fragments of a Fern [Glossopteris 1) also occur in the shale. The JEsthericB 

 are much smaller than the generality of those in the sandstone of Mangali (figs. 16 

 and 20), but have a round-ended oblong outline not unlike that of some individuals 

 from this locahty^ (compare figs. 21 and 24). The surface of the valves exhibits, under the 

 microscope, about ten delicate, concentric ridges, separated by interspaces usually smooth, 

 or traversed by faint lines parallel to the ridges, but occasionally ornamented towards the 

 ventral border by a pattern consisting of slight, vertical, anastomosing wrinkles, with 

 accompanying rows of minute pits (fig. 25, magn. 100 diam.) No such ornament as this 

 is traceable in any of our numerous individuals of E. Mangaliensis, nor do the latter 

 show the faint concentric striae of the interspaces, but either a blank smoothness or an 

 obscurely hexagonal reticulation (figs. 17, 18). Although Estheria having a reticulate 

 ornament do sometimes take on a transversely barred or wrinkled pattern also (as in 

 E. ovata, E. Murchisonice, E. minuta var. JBrodieana (of Linksfield), &c. yet the latter may 

 be the essential and sole ornament of a species (as in E. ellipticd) ; and this may be the 

 case here. 



In its different style of ornament, therefore, as well as in its fewer ridges, squarer 

 outline, smaller size, and thinner valves, the Estheria from Kota difiers considerably from 

 E. Mangaliensis. 



The Fish-shale, limestone, and Estherian shale of Kota* are regarded by Mr. Hislop as 

 of Lower Jurassic (Liassic) age, and as lying above a sandstone, with plant-remains, pro- 

 bably equivalent to the plant-bearing sandstone of Nagpur (Letter, July 19th, 1861), 

 and the latter is on the geological horizon of the " Damuda group," of Bengal (See the 

 Table, page 80). 



1 Cypridce are also found (generally compressed) in the bituminous shales of Kota, in which Lepidotus 

 Deccanensis, L. longiceps, and L. brevieeps occur, with Plant-stems and Glossopteris (?). In the lime- 

 stone at Kota, Fish-remains {^chmodus Egertoni and Lepidotus) occur ; also Teleosaurian remains, Sphe- 

 nopteris, &c., 'Bombay Asiat. Soc. Journ.,' vol. vi, p. 201. 



2 Hence I was at first led to regard the two forms as probably belonging to the same species. Op. cit., 

 pp. 348 and 353. 



3 For notices of the Fish-shales and limestone of Kota, see ' Quart. Journ. Geol. Soc.,' vol. vii, 

 p. 272 ; viii, p. 231 ; ix, p. 351 ; x, p. 371 ; and xvii, p. 36 ; also 'Journ. Bombay Asiat. Soc.,' vol. vi, 

 p. 201. 



