neighbourhood of Grantham. 57 



gold of California, may be in store for us. In our Inferior Oolite, 

 corals are more or less distributed throughout the whole; but no 

 one stratum contains them in greater abundance than the oolite 

 marl, the upper division of which at Crickley has been correctly 

 denominated the u coral bed," and evidently formed an exten- 

 sive coral reef beneath the ocean ; but with the exception of the 

 pisolite, we have no further evidence of such reefs in any of the 

 other superior or inferior beds. Hence the abundance of corals 

 in the oolite marl near Grantham, coupled with other facts, such 

 as the frequency of Nerinatce, which are usually found associated 

 with corals, and are believed to have inhabited shallow seas, tends 

 to support the probability that the marl in Lincolnshire was de- 

 posited under similar conditions to the marl in Gloucestershire, 

 although many of the shells may be distinct, a very little geo- 

 graphical distance in a sea-bottom being often sufficient to pro- 

 duce a corresponding increase or decrease in the number and 

 variety of species. 



I observed the marl occupying a similar position nearer Gran- 

 tham, where it is harder, whiter, and extensively used for roads, 

 and contains many small shells and corals. The soft, white and 

 yellow oolite (no. 3, p. 56) affords many small shells, and forms a 

 tolerable building-stone; but as it is never quarried deep, I could 

 not ascertain its thickness, nor the nature of the lower strata ; 

 but there must be a considerable mass of oolite probably inter- 

 vening between it and the subjacent lias. One of the numerous 

 trial -borings on Harrowby Hill near Grantham gives the following 

 section : — 



ft. in. 



Soil 6 



Rubble 6 



Inferior oolite 40 6 



Lias (blue bind) continued downwards . . 10 



by which it appears that thereabouts the total thickness of the 

 Inferior Oolite does not exceed 41 feet. As a portion of no. 3 

 is a friable freestone, it may be considered as the representative 

 of the shelly freestone underlying the ' oolite marl ' at Leck- 

 hampton. Nearer Grantham also there is a fragmentary, shelly 

 oolite on the side of Ponton Hill, which is possibly a continua- 

 tion of the same bed ; but a more accurate investigation is re- 

 quired before this can be positively determined. There are so 

 few natural or artificial sections in the country that it is ex- 

 tremely difficult to obtain correct information ; and although two 

 lines of railway are now being constructed, the engineers em- 

 ployed know nothing of geology, and are therefore incapable of 

 rendering any assistance. 



In the Institution at Grantham there is a very tolerable col- 



