DRIFTS OF THE YALE OF CLWYD, 



91 



It is interesting to note the occurrence of Cyrena (Corbiculct) 

 fluminalis in these beds, which (though, as pointed out to me by 

 Mr. Clement Beid, it ranges down to the Cromer Forest-bed) is such 

 a common and characteristic fossil in the March Beds and the post- 

 glacial river- terraces of the south-east of England — the valley of 

 the Cam, for instance (cf. Searles Wood, Geol. Mag. vol. ix. 1872). 

 See also : — 



Phillips, Quart. Journ. Geol. Soc. vol. xxiv. 1868, p. 250. 

 Wood and Home. Quart. Journ. Geol. Soc. vol. xxiv. 1868, 

 p. 146. 



Hall. Liverpool Geol. Soc. Dec. 11, 1866. 

 Seaeles Wood. Geol. Mag. vol. viii. Sept. 1871, p. 406. 

 Lamplugh. Yorkshire Geol. Polytech. Soc. 1879, pp. 8, 9. 

 Juxes-Browne. Quart. Journ. Geol. Soc. vol. xxxv. 1879, 

 p. 397. 



All the beds from which the fossils were obtained which are 

 recorded in columns I. to TIL must be considered to belong to an 

 age when severely arctic conditions had ceased to prevail, and which 

 therefore may be called Postglacial. 



In column VIII. I have indicated the shells which have been 

 obtained from the Bridlington Drift. When examining the Dim- 

 lington Section some years ago, in company with Mr. Leonard Lyell, 

 I noticed in the lower part of the cliffs a short lenticular mass of 

 greenish sand full of shells. It was so small that we worked it out 

 completely. In it we found Nucula Cobholdice perfect and Astarte 

 compressa with valves adherent, and seven other species (see Hughes, 

 " On the Evidence of the later Movements of Elevation and Depres- 

 sion in the British Isles," Vict. Inst, or Phil. Soc. Great Britain, 

 March 15, 1880, p. 8). Mr. Lamplugh has since procured shells 

 from similar beds in the same neighbourhood, and has well worked 

 out the equivalent Bridlington Drifts (Brit. Assoc. 1881 ; Geol. 

 Mag. dec. 2, vol. v. p. 509, vol. vi. p. 393, vol. viii. 1881, p. 535, 

 vol. ix. p. 383 ; Quart. Journ. Geol. Soc. vol. xl. 1884, p. 312, in 

 which are notes by Gwyn Jeffreys, E. T. Newton, and Dr. Crosskey ; 

 Proc. Geol. Polytech. Soc. Yorkshire, pt. i. 1881, p. 383, pt. ii. 1882, 

 p. 27, pt. iii. p. 240, 1883). 



See also : — 



Beak, ¥i. " A short account of an interesting deposit of 



Eossil Shells at Bridlington Quay," Loudon's Mag. Nat. Hist. 



vol. viii. 1835, p. 355. 

 Young: and Bird. Geol. Survey Yorksh. Coast, 1822, p. 22. 

 Sedgwick. Ann. Phil. 1826, ser. 2, vol. ix. p. 339. 

 Phillips. Brit. Assoc. 1835, Trans. Sect. p. 62 ;" Geology of 



Yorkshire, 1835, p. 40 (in the 3rd edit. p. 274, there is a 



note by Gwyn Jeffreys). 

 Lyell. Ann. & Mag. " Nat. Hist. vol. xii. 1839, p. 324; 



' Antiquity of Man,' 1873, p. 266. 

 Eoedes. Mem. Geol. Surv. vol. i. 1846, p. 392. 

 Searles Wood. Crag Mollusca, 1847-55. The Bridlington 



drift was then believed to be about the horizon of the 



