384 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [Feb. 29, 



obtained with difficulty, the list is consequently very limited ; some 

 of those, however, which I broke all contained fossils in moderate 

 numbers. Could this bed be worked, I have no doubt other species 

 might easily be added to our list. The Upper Pecten-bed is overlain by 

 about 5 feet of dark laminated shales (i), in which I found no fossils. 



The greyish limestone and shales (g to a), containing Modiola 

 oninima and Ostrea liassica, which succeed the Avicula contorta 

 beds, attain a thickness of from 18 to 20 feet. I regard this series 

 as the equivalent of the Lower Saurian beds at Street. These beds 

 will be described in detail under that section. 



The Am. planorbis bed (b) is represented by dark-greyish la- 

 minated shales containing compressed shells of Ammonites jplanorbis, 

 Sow., which are inclined at an angle of 45° high up in the cutting, 

 and have been very much disturbed by the. upraised limestone. 



The alternate beds of light-coloured limestone and shales (a), 

 highly inclined and much fractured, appertain to the zone of 

 Ammonites Bucklandi, as in them I found portions of Lima gigantea, 

 Sow. These beds very much resemble similar strata of the A. 

 Bucklandi series seen in situ at Up-Lyme, and which will be de- 

 scribed in the sequel. 



Watchet. — The Avicula, contorta beds are exposed in a coast-sec- 

 tion at Watchet, where the zone of Am. jplanorbis has been long 

 known from its having yielded shales containing the original speci- 

 mens of Ammonites jplanorbis and Am. Johnstoni, first figured by 

 Sowerby in the ' Mineral Conchology.' The nacreous layer of the 

 shells is beautifully preserved in these Ammonites from Watchet. 



The Bone-bed here consists of a hard, bluish-grey, sandy lime- 

 stone, about an inch in thickness, containing fragments of bone, with 

 teeth and scales of Fishes. In the bands of sandstone small shells 

 (Ptdlastra arenicola) are found in the state of moulds. 



Beer-Crocomb.— My friend the Rev. P. B. Brodie informs me 

 (September 25, I860) that at Beer-Crocomb, about five miles from 

 Ilminster, in Somersetshire, he found several years ago the Insect- 

 limestone, which contained wings of Orilioplilebia, elytra of Coleo- 

 jytera, a few small Ammonites, Aptychus, &c. There were several thin 

 beds of limestone divided by layers of clay, but not so thick as those 

 in Warwickshire. Near the quarries, on the banks of the Bridge- 

 water Canal, the Bed marl with gypsum is seen, which was dug out 

 in forming the tunnel some years previous to 1847. On the spoil- 

 banks were blocks of a light- coloured limestone, which lithologically 

 resembles the " Cypris-bed," between the Insect-limestone and the 

 Bone -bed, in Gloucestershire and Warwickshire. It contained a 

 considerable number of small univalve and bivalve shells in good 

 preservation. The exact position of this fossiliferous band could not 

 be seen in situ ; but it probably lies beneath the Insect-bed, between 

 that band and the Red marl. Mr. Brodie has kindly sent me the spe- 

 cimens which he collected at Beer-Crocomb ; and I have found them 

 to resemble the fossils that I collected from the same stratum at 

 Uphill. The Beer-Crocomb shells are in fine preservation : besides 

 several forms unknown to me, I have found the following species : — 



