326 MK. 0. A. SHRUBSOLE ON TRIASSIC PEBBLES OF [Aug. 1903, 



The Museum of Practical Geology in Jermyn Street contains the 

 following species found in pebbles in the Bunter by Prof. Bonney 

 and Mr. S. G. Perceval:— 



Orthis budleighensis Cannock Chase. 



Branching coral Two small fragments. Same district. 



Trachyderma serrata (?) Near Lichfield. 



Cornulites serpularius "") T a ... , ,., „ , , 



Strophomenasp 1 In one flattwh pebble of dark- 



Favositessp.J \ orange sandstone. Cannock 



Atrypa reticularis ) 



Pefraia bina ? (cast) Tamworth. 



In addition to these, Prof. Bonney x has reported the occur- 

 rence of 



Bhynchonetta sp. 

 Orthis sp. 

 Glyptocrinus. 



Lingula Haivkei (Rouault) 

 = L. Bouaulti (Salter). 



This list is a somewhat disappointing one. I think it likely 

 that other species may have been found, which have unfortunately 

 not come to my knowledge. The above list, however, contains 

 three southern forms, Orthis budleighensis, Lingula Haiukei, and 

 Trachyderma serrata (1), which have to be accounted for ; but the 

 number of specimens is too small for the purpose of comparison. 



Fortunately, we are not dependent upon specimens obtained 

 in situ from the Bunter. It is well known that vast quantities of 

 pebbles from the Bunter occur in the various gravel-deposits which 

 are found not only near the outcrop of the Conglomerate, but 

 spread far and wide along the upper slopes of our river-valleys. 

 They are very plentiful, for instance, in the Thames Valley, and 

 may be traced up the valley of the Evenlode, almost without a 

 break, up to the district around the Lickey, where the Conglomerate 

 is marked on the map, although it is obscured by its own Drift. 



Owing to their being spread over a larger area, and to the great 

 attention which has been paid to the problems connected with the 

 Drift, these pebbles have been studied by a number of observers, 

 and a not inconsiderable list of fossils has been obtained. The 

 Rev. P. B. Brodie gave a good deal of attention to the Drift around 

 Warwick, and the results which he communicated to this Society 

 are most important and interesting. 2 He pointed out the close 

 relationship of the fauna of these pebbles with that of Budleigh 

 Salterton. 



There is naturally an element of uncertainty as to the origin of 

 derived pebbles or fragments. That element, however, is assuredly 

 very small when they contain fossils, and smaller still when the 

 fossils as a whole present strongly-marked or special characters. 3 

 The slight element of uncertainty which is left is not sufficient to 



1 See Geol. Mag. 1880, p. 406. 



2 Quart. Journ. Geol. Soc. vol. xxxvii (1881) p. 430. 



3 A pebble crowded with Orthis budleighensis from Sparkbrook, Birmingham, 

 may be compared with a similar pebble from Budleigh Salterton. Both are in 

 the Museum of Practical Geology, Jermyn Street. 



