1853.] MORRIS — LINCOLNSHIRE OOLITES. 3.37 



and massive corals, and many specimens oi Nerincea. These lower 

 marine beds frequently contaiir the remains of plants that must have 

 been drifted from the neighbouring land. In the marly beds above 

 the slates at Collyweston, the Pecopteris polypodioides, Brong., not 

 Lindl., is of frequent occurrence ; in a similar position at Tinkler's 

 quarry near Stamford fronds of 'Pterophyllum are found, as also tvi'o 

 species of the same genus at the Barnack quarries. In connection with 

 these facts, it may be observed, that the Fern described by Lindley and 

 Hutton* as obtained from the Wealden of Wansford, in Northamp- 

 tonshire, belongs to the lower oolitic beds above the slates, and con- 

 sequently the statement of the occurrence of the Wealden in that lo- 

 cality is erroiieous. The upper beds or shelly rags of the Great Ponton 

 Cutting, which are equivalent to the freestones of Ketton, Casterton, 

 and Ancaster, and the shelly oolites of Barnack, vary from a 

 coarse to a fine-grained structure, and contain in some places a fine 

 and numerous suite of Testacea indicating somewhat an approach to 

 littoral conditions. In the Ponton Cutting successive zones of Tere- 

 bratula were accumulated, associated with a species of Lima ; these 

 portions of the rock are more crystalline than that in which the 

 mass of species (before enumerated) were found. One marked 

 feature in these oolitic beds is the almost entire absence of Cepha- 

 lopoda ; in all the collections formed in this district, I have seen but 

 one or two specimens of Ammonite and Belemnite ; their entire ab- 

 sence in the middle beds of the inferior oolite of the West of Eng- 

 land is well known, and also the comparative rarity of them in the 

 Great Oolitef of the South of England. In the Great Oolite of the 

 Yorkshire coast about four species have been obtained. 



The argillaceous strata which next succeed, and form so important 

 a feature in the Railway cuttings, have been traced over a considerable 

 area in this district. Their southern extension has been traced in 

 some spots on the oolitic range which separates the Welland and 

 the Nen, as at Weldon and the Wood pit near Wansford ; at Ketton 

 and the neighbourhood of Stamford they are fully developed, and they 

 also cover in many places the oolite on each side of the railway, forming 

 a part of the argillaceous lands of the county. In the district of the 

 Drift they appear to cease, having been rem^oved by denudation, and 

 it is very rare to find a trace of them underlying that deposit. North 

 of Grantham they occur at x'\ncaster and intervening spots towards 

 Lincoln, where patches also are found. 



* Lonchopteris Manfelli, Fossil Flora, t. 171. See also Mr. Lonsdale's note 

 in Dr. Fittou's Memoir, Geol. Trans. 2 ser. vol. iv. p. 383*. 



t Ten species are described in the Monograph of the Mollusca of the Great 

 Oolite (Palffiontographical Society) : viz. five Ammonites, three Nautili, and two 

 Kelemnites. 



