476 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Terebratula punctata. 



Thecidium Bouchardii. 



— -,sp. 



Avicula. 



Gryphaea incur va, Sow. 



Lima, sp. 



,sp. 



Pecten. 



Plicatula spinosa, Sow. 



Astarte, sp. 



Trochus epulus, Stol. 



Turbo. 



Belemnites acutus. 



clavatus. 



Tee til of fishes, with Encrinital stems derived from the Carboniferous Lime- 

 stone. 



The organic remains from the Middle and Upper Lias, numbering 

 about 580 species, have been noticed by me in a Memoir " On the 

 Middle and IFpper Lias of the South-west of England," in the Pro- 

 ceedings of the Somersetshire Archaeological and Natural History- 

 Society for 1865-66. 



4. Relative Thickness of Secondary Beds within and beyond the 

 Somersetshire Coal-basin. — Having already referred to the thinning 

 out and comparative insignificance of the Triassic beds within the 

 coal-basin, as compared with their representatives beyond, we are 

 enabled by the sections that have been given to realize the same fact 

 with regard to the formations above. The Lower Lias, which is 

 estimated at 700 feet, is at Munger reduced to 18 inches. The 

 Middle and Upper Lias on the Dorsetshire coast is described by Mr. 

 Day as 500 feet thick *. The latter, though thin in Somersetshire, is 

 known to attain a very considerable thickness in Yorkshire. Above 

 the Upper Lias there is again a great hiatus in the Oolitic series, no 

 beds below the Upper Eagstones of Gloucestershire having been 

 observed in any sections in the districts around Bath, the beds thus 

 wanting, judging from the estimate of Dr. Wright in the Cleeve 

 Hillf section, being 170 feet thick. 



Comparing the greatest thickness of the Secondary beds without 

 the coal-basin with the greatest reduction above the Coal-measures 

 within it, we arrive at the following remarkable result : — 



Without Within 



Coal-basin. Coal-basin. 



ft. ft. 



Triassic beds 2000 50 



Ehffiticbeds 50 50 



Lower Lias 700 2 



Middle and Upper Lias 500 42 



Inferior Oolite 170 25 



3420 169 



5. Whatley Lias and Fontaine-etoupe-Four. — The intimate rela- 

 tions, both stratigraphical and palseontological, which exist between 

 the Upper-Lias Leptsena-beds of Ilminster and those of Curcy, May, 

 and Pontaine-etoupe-Pour, in Normandy, are very remarkable. At 

 Hminster these Leptsena-beds are only 18 inches in thickness, and 

 are overlain by the Saurian and Fish-bed with its numerous beautiful 



* " On the Middle and Upper Lias of the Dorsetshire Coast," bv E. C. H. Day, 

 Esq., F.G-.S., Quart. Journ. Geol. Soc. vol. xix. p. 279. 



t "Additional Notes on Cleeve Hill Section," by T. Wright, M.D., F.R.S., 

 F.G-S., Proceedings of the Cotteswold Naturalists' Field-club, 1865. 



