181 



No. 9, G.— Blue shales of the Upper Lias, with Ammonites 

 radians, Am. serpentinus. 



No. 10, B-.—Marlstone, with Ammonites spinatus, 115 feet. 

 No. 11, I.— Clays of the Middle Lias, forming the northern 

 slope of the hill; they are well shewn in the brick-yards near 

 the base, and contain Ammonites caprieornus, Am. Henleyi, Am. 

 Ihez, Am. hipunctatus. 



No. 12, K. — Jamesoni zone, base of the Middle Lias. 



1st. — Zone of Ammonites Muechison^. 

 Assuming that the "Feuillet grezeux a Chondrites scoparius, 

 ThioUiere," and other Fucoids, with the remains of Ammonites 

 opalinus, is the equivalent of the Ammonite bed, capping the 

 sands of the Upper Lias, we can have no difficulty in instituting 

 a rigid comparison between the lower division of the Inferior 

 Oolite, as given in M. de Fekkt's section, and those exposed in 

 the Cotteswold Hills. 



The calcaire a Pecten personatus and calcaire a Entroques 

 are, with us, represented by the Pea Grit and its underlying 

 ferruginous bed, and in some localities, as at Frocester Hill, 

 (Fig. lY., p. 169 ;) this zone is a hght, cream-coloured, gritty, 

 crystalline oolite, traversed at intervals by extremely crystalline 

 shelly layers. A great portion of the rock is composed of the 

 fragments and plates of Crinoidea, the plates and spines of 

 Echinidae, and comminuted fragments of the shells of Mollusca. 

 This calcaire a Entroques at Frocester Hill has a most remarkable 

 crystalline character, and, when lit by the sun's rays, glistens 

 most brilliantly. 



In the neighbourhood of Cheltenham (as at Cleeve, Dowdes- 

 well, Leckhampton, Crickley, and Birdlip,) it is well developed ; 

 but in the southern Cotteswolds it becomes thinner, and at 

 Dundry Hill, near Bristol, and in Somersetshire and Dorset- 

 shire, a mere rudiment of this division is found. If we apply 

 the Palseontological test to the physical correlations, we find 

 additional evidence of their identity, for all the leading fossils 

 collected by M. J. Martin, and enumerated in M. de Feeey's 

 lists, are the characteristic species of our Murchisonse zone. 

 Thus we have : — 



