Excursions of the Geologists' Association. 331 



position in which these masses are now found, it is not probable 

 that they represent actual coral reefs, such as are at present growing 

 in the Indian and Pacific Oceans, but rather that they are the results 

 of drifted masses, like the Bermuda reefs, partially grown over by 

 other corals, and full of shells. About one hundred feet of Kim- 

 meridge-clay rests on the water- worn surface of the last formation. 

 It is tolerably uniform in its composition ; and produces fine Selenite 

 crystals, especially in its lower parts. The upper beds are the most 

 fossiliferous, and abound with the remains of Saurians ; Ostrea 

 deltoidea the most characteristic fossil. Sandy beds of Portlandian 

 age succeed, and the whole is capped by an Ironsand series of 

 Wealden age, about eighty feet in thickness. The party had an 

 •opportunity, under the guidance of "Mr. Parker, of verifying the 

 a!bove remarks, by actual inspection of the numerous pits and quar- 

 ries between Oxford, Shotover, and Heddington. 



On the following day an early start v/as made. Prof. Phillips 

 •conducted the party to Charlbury, and was ably assisted by Mr. 

 Parker, who served out to each member a lithographic map of the 

 valley of the Evenlode, drawn and geologically coloured by himself. 



From Charlbury on the West to Handborough on the East, a 

 distance of about seven miles, there occur the following formations, 

 commencing from the West : 



feet I i Stonesfield Slate. 



Marlstone 16 | < Great Oolite. 



Upper Lias 10 I ( Forest Marble. 



Inferior Oolite ... ,.. 12 | Conibrash. 



Walking back from Charlbury along the line, the party entered 

 a cutting of Inferior Oolite, and the members immediately pro- 

 ceeded to hunt for fossils. The Oolite here is a pale yellow Eag- 

 stone, containing a fair number of shells belonging to the Clypeus 

 grit, which is probably the topmost member of the Parkinsoni zone. 

 Opposite Fauler the Marlstone is being excavated for Ironstone- 

 Here there is a fine section, exhibiting the Marlstone, Upper Lias, 

 and Inferior Oolite, one above the other, in the most striking contrast. 

 The whole section cannot exceed forty feet, and xhis is all that repre- 

 sents beds, which, at Cheltenham, attain a thickness of more than 

 six hundred feet. The Upper Lias consists of blue sandy clays (not 

 obviously fossiliferous), and on this rests the yellow rubbly Inferior 

 Oolite. A remarkable feature here is a thin bed of rolled shells and 

 pseudo-pebbles, resembling the Dogger of the Yorkshire coast. 

 Instead however of Terehratula trilineata, the chief shell here is 

 BhyncJionella tetrahedra. 



The party now bid farewell to Prof. Phillips, who found it 

 necessary to return,' and proceeded towards Stonesfield under the 

 guidance of Mr. Parker. Piles of debris, the res alt of ages of 

 raining for " Slate," are here seen to cover the hill-side. Several 

 good things were obtained by members of the party. The most 

 common shells appear to be Tngonia impressa and GervilUa acuta, 

 generally small. Traversing the Great Oolite and Forest Marble, 

 the party returned by way of Handborough to Oxford. 



' This was his last farewell to the Association, he died on the 24th April. See 

 Geol. Mag. for May, page 240. 



