164 



Notices of Books : 



[[JuLV 



" Following the section from the coal downwards, we meet with 

 an earthy limestone which though naturally dark becomes mealy and 

 whitish on the surface by exposure, it is perhaps the magnesian 

 limestone of the coal measures. This bed is about four feet in thick- 

 ness, and contains nests of coal, with some traces of shells; a layer of 

 randstone an inch in thickness divides this from a bed of ordinary 

 compact limestone twenty feet in thickness, containing few if any 

 shells ; — an interesting circumstance when compared with the fact of 

 the absence of fossils in limestones of similar character in Central 

 India, a more compact and crystalline bed than the last, abounding 

 in shells occurs. This is separated from the great sandstone, by a 

 fine calcareous grit stone eight feet in thickness, in which only one 

 fossil was found. 



*' Nummulite limestone was first brought to light at the foot of the 

 Kasya mountains by Mr. Colebrooke in his paper on Mr. Scott's 

 notes and specimens, which were forwarded to the Geological Society 

 in 1824;* but the Cherra Ponji bed of shell limestone here noticed 

 was first observed in 1832 by Mr. Cracroft, t Mr. Scott may have 

 previously found occasional shells in the same rock in the Kasya as 

 well as in the Garrow mountains.:|: It does not however appear that any 

 chronological distinction has been established between the different 

 limestones in this quarter, although the Cherra rock is distinguished 

 as a formation from the nummulite limestone, as well by means of its 

 fossils, as by the beds with which it is associated. 



" The nummulite limestone of Terriagat,where it composes that por- 

 tion of the Laour hills situated at the base of the Kasya mountains, is a 

 compact blue rock alternating in single strata with a coarse earthy 

 oolite of a calcareous nature. § These appear to rest (as well as could 

 be determined during a cursory examination while passing) on a slate 



" * Geol. Transac. vol. 1, 2(1 series, 132," *'t Jour. Asiat. Soc. vol, 1,352.** 

 *' t Geol. Transac. vol. 1, 2d series, 132." 

 " ? Although 40 geographical miles distant from Silhet, it is named in Mr. Colebrooke*5 

 paper, JSilhet limestone ; but as other limestones may be found nearer Silhet, the neces- 

 sity of being more definite in our allusions to localities in India is obvious. In the fol- 

 lowing vol. of the same transactions, this rock (supposing it to be the Silhet limestone) is 

 said to be v/hite, and also to contain in the Garrow mountains vertebrae of a fish ; but un- 

 less we presume that the Revd. Dr. Buckland, the eminent author of the paper in question, 

 identified these in Mr. Scott's specimens, and that they were overlooked by Messrs. Clift 

 and Webster who examined them for Colebrooke's paper, we must attribute the state- 

 ment to a similar vague indication of localities as that above referred to, as we look in 

 vain for an instance of Mr. Scott having found vertebrae of fishes in the nummulite lime- 

 stone, although such were found by him in the sands and clays Qf the Caribari hills, as ap- 

 pears from the list of fossils ia CQlebrooke's paper." 



