Vol. 69.] 13ATHONIAN ROCKS OF THE OXFOUD DISTRICT. 503 



only about eighty can be said to be at all common. Paloeonto- 

 logically, the only beds that can be recognized are as follows : — 



Cornbrash, characterized by Psettdomonotis echinata, Gressh/a peregrina 

 Terehratula intermedia, Ornithella oho va ta 

 and Pygurus rnichelini. 

 Great Oolite. Block 1. Gervillia waltoni, Nerincea eudesii, and Tere- 



hratula bathonica. 

 1st & 2nd ' max Mala ' Terehratula bathonica, large and abundant. 



Beds. 

 Nerincsa Rock. 'Nerincea cf. funiculus. 



Fullonian. Inocera/mus obliquus, Ehynchonella sp., Clypeus 



Bhynchonella & Inoccra- midleri, and Ostrea sbwerbyi. 

 onus Beds. 

 Stoneslield Slates, charac- 

 terized by Trigonia impressa. Gervillia acuta, and Stigo- 

 ceras micromphalus. 



R. F. Tomes : mentions thirty-four species of corals from the 

 Bathonian, and divides them into seven bands, according to the 

 localities from which they came. Of these, No. 1 is probably 

 below the Stonesfield Slates, while Nos. 2, 3, & 4 are probably of 

 the same age, since Mr. Walford mentions a coral-bed at Stones- 

 field just above the 'slates', 2 and on his own showing No. 2 is 

 precisely in that position. Nos. 5 & 6 probably represent the coral- 

 bed in Gibraltar Quarry, which grew on the eroded surface below 

 the First Terehratula Bed, and the coral-bed in the Fossiliferous 

 Cream-Cheese Bed of the Oxford Portland-Cement Works. Bed 7 

 occurs in the Cornbrash at Fairford ; this latter is of interest, 

 since Stylina and Thamnastrcea arachnoides are recorded from the 

 Cornbrash near Buckingham. 3 Th. arachnoides is so typically 

 Corallian, where it occurs with Stylina delabechei, that one feels 

 some doubt as to whether this does not represent a small faulted 

 outlier of Corallian. 



A peculiar Structure referred to Annelid-Tubes from 

 Bed h of the Chipping-Norton Limestone of the 

 Ardley Section. (PL XLVIII, tigs. 3 & 4.) 



In this rock, which is a fine-grained argillaceous limestone, a 

 number of curious circular rings of coarse material are seen in 

 section. A vertical section shows that these rings are produced 

 into a tube, the total length of which is unknown. 



The external diameter of the rings varies in different specimens 

 from 10 to 20 mm. ; the length, so far as can be seen, is about 

 30 mm. When the rock has become disintegrated by wet and 

 frost, these tubes are found to be closed in at the base. A micro- 

 scope-section shows them to be composed of small shell-fragments 



1 Q,. J. G. S. vol. xxxix (1883) pp. 178-74. 



2 E. A. Walford, Bep. Brit. Assoc. (Oxford) 1894, p. 304 ; ibid. (Ipswich) 

 1895, p. 415 ; and ibid. (Liverpool) 1896, p. 356. 



3 A. H. Green, 'Geology of the Country round Banbury, &c.' Mem. Geol. 

 Surv. 1864, p. 32. 



Q.. J. G. S. No. 275. 2 l 



