Mr. J. Lycett on the Uppei- Lias of Gloucesteiskire. 257 



3, 4, 5, 6. Upper Lias ; no fossils visible in this section. 



7. Marlstone or Middle Lias. 



S, 9, 10. Lower Lias ; but little exposed. 



In Sii' R. L Murchison's little sketch of the ' Geology of Chel- 

 tenham/ the thickness of the Upper Lias is estimated at 60 or 

 70 feet ; and the following fossils were collected by him from a 

 road- side cutting near Sandy well Park : — Ammonites bifrons, 

 A. undulatus, A. annulatus, Belemnites acutus, B. tubularis, B. 

 penicillatus, Inoceramus dubius, Plicatula spinosa, Trochus bisectus, 

 Area, Gervillia, Lucina, IModiola, Nucula, Naiitilits, Pholadomya. 

 In the second and enlarged edition of the same work^ the authors 

 estimate the general thickness of the Upper Lias at 100 feet ; 

 to the fossils given in the former edition are added the follow- 

 ing : — Ammonites falcifer, A. Strangwaj/sii, Belemnites Bru- 

 guierianus, Trochus bisertus, Nucula rostralis, ^schna Brodiei, 

 Astacus, Hippolita, Cidaris minuta. In the memoir by Mr. Hull, 

 the Upper Lias is stated to be upwards of 230 feet thick at 

 Leckhampton Hill; it is estimated to be 300 feet at Cleeve 

 Cloud ; in the hills further northwards, at from 80 to 100 feet ; 

 it constantly declines in thickness towards the Oxfordshire 

 boundary of the county, so that at Burford its thickness is only 

 6 feet. In the southern portion of the Cotteswolds it is stated 

 to be only 10 feet thick at Wootton-under-Edge, and about 

 30 feet at Stroud ; but I shall have to show that at Nailsworth, 

 a spot situated between the two latter places, the thickness 

 of the Upper Lias is upwai-ds of 105 feet. The only additional 

 fossils mentioned by Mr. Hull are Nautilus inornatus and Belem- 

 nites abbreviatus. 



The sections upon which the present remarks are founded 

 were made in forming several deep drains and a cutting for a 

 camage-drive upon a steep hill-side preparatory to building a 

 villa and laying out the surrounding ground for ornamental 

 pui-poses, upon the western side of the valley, and immediately 

 adjoining the village of Nailsworth ; it also happened about the 

 same time that a cutting was made along the whole course of 

 the turnpike road in the same valley, towards Stroud, for the 

 purpose of laying down gas-pipes ; another small section was 

 also afforded by some alterations made in the mill-stream at 

 Holcomb Mills, about half a mile higher up the valley. The 

 deep-drain sections afforded a view of the higher beds of the 

 stage, even to their junction with the micaceous marly sands of 

 the Cynocephala-stage ; the other cuttings exposed the lower 

 beds, but less perfectly than the upper ones, and also some por- 

 tion of the Marlstone series. But although a portion of nearly 

 the whole of the beds was uncovered, the entire area from which 



