264 Rev. P. B. Brodie on the Geology of the 



marlstone abounding in fossils is largely developed, and also in 

 the descent from Denton Hill into the valley in which Grantham 

 stands. It there occupies the same relative position, and pre- 

 sents 4he same geographical features as it does in Gloucester- 

 shire, Warwickshire and Somersetshire. 



A railway cutting through Gonnerby Hill close to Grantham 

 has exposed the top beds of the Lower Lias, undistinguishable 

 either lithologically or zoologically from their equivalents at 

 Hewlett^s and Robinswood Hills near Cheltenham and Gloucester. 

 The ochraceous and laminated lias of Professor Buckman, with 

 their characteristic fossils, are well seen in a deep cutting, in the 

 latter of which, nodules and layers of ironstone are extensively 

 distributed. -The specimens which I procured, and the collec- 

 tions I saw from this part of the series, agree precisely with those 

 obtained in similar strata in Gloucestershire. This division of the 

 Lias constitutes comparatively low hills N.W. of Grantham, not 

 capped by oolite, which takes a more northern course towards 

 Lincoln. A considerable portion of the former town stands upon . 

 sand and gravel, but the lower division of the Lias has been pene- 

 trated for wells to the depth, as I was informed, of ninety feet ; but 

 from the difficulty I had in obtaining sections in any of the in- 

 ferior strata, I am unable to say whether it agrees exactly in this . 

 respect with those in the Vale of Gloucester. The Lower Lias 

 generally may be best studied N.W. and W. of Grantham, on 

 the S. and S.E. of which the oolitic Wolds rise and rarely display 

 the Upper Lias at their base. West of the town towards Notting- 

 ham the junction of the red marl and lias is probably visible, 

 though I did not myself see it; at all events the 'Insect Lime- 

 stone' occurs at Granby between Denton and Nottingham, for 

 in the Grantham Museum there is a beautifully perfect fish, ap- 

 parently a Dapedium, from this stratum ; the structure of this 

 limestone being so peculiar, that in the absence even of insect 

 remains, I had no difficulty in recognizing it. In this case, this 

 is the furthest point northwards in which it has been hitherto 

 detected ; and as it is largely quarried at Barrow on Soar near 

 Mount Sorrel in Leicestershire, its course may in all probability 

 be traced southwards with tolerable regularity into Warwickshire, 

 Worcestershire and Gloucestershire ; and it may extend, and very 

 likely accompanies the red marl in its range still further to the 

 north, perhaps even to the north-eastern coast of Yorkshire. 



The Gravel. 



The gravel in places near Grantham, especially at Ponton 

 Hill, two miles south of the town, is extremely interesting, and 

 there of some extent and thickness. It is mainly composed of 

 the debris of the inferior oolite, chalk flints, and other older 



