I58 BIBLIOGRAPHY OF YORKSHIRE GEOLOGY. 
18 Dakyns, J. R. — The Purple Boulder Clay at Holderness. 
Geol. Mag., dec. ii., vol. vi., p. 528. 
19 , C. Fox-Strangways, R. Russell, and W. H. Dal- 
ton. — Explanation of Quarter-sheet, 92 S.E. of the 
Geological Map of England and Wales, illustrating the 
geology of the Country between Bradford and Skipton. 
Geological Survey Memoir, pp. 20. 8vo. London. 
20 Dalton, W. H.— [See J. R. Dakyns]. 
21 Davis, J. W. — On the Occurrence of certain Fish Remains 
in the Coal Measures, and the evidence they afford of 
Fresh-water Origin. Proc. Yorks. Geol. Soc., vol. vii., 
pt. 1., pp. 40-52. Rep. Brit. Assoc. for 1878, p. 539 
(Abstract). 
22 Goredale Scar. [Descriptive of a photograph]. Proc. 
Yorks. Geol. Soc, vol. vii., pt. 1, pp. 83, 84. 
23 On the Source of the Erratic Boulders in the Valley 
of the River Calder, Yorkshire. Geol. Mag., dec. ii., 
vol. vi., pp. 313-321. Proc. Yorks. Geol. Soc, vol. vii., 
pt. ii., pp. 141-154. 1880. 
24 The Calder Valley [In answer to Mr. Dakyns]. Geol. 
Mag., dec. ii., vol. vi., p. 191. 
25 Description of a new Species of Fossil Fish Spine, 
Ctenacanthus minor, from the Lower Coal Measures of 
Yorkshire. Ibid., p. 531. 
26 Notes on Pleurodus affinis sp. ined. Agassiz, and 
Description of three Spines of Cestracionts from the 
Lower Coal Measures. Quart. Journ. Geol. Soc, vol. 
xxxv., pp. 181-188. 
27 On the Discovery of certain Pockets of Chipped Flints 
beneath the Peat on the Yorkshire Moors, near Halifax. 
Rep. Brit. Assoc for 1879, p. 395. 
28 De Rance, C. E. — Notes on some Triassic Borings [Middles- 
brough]. Trans. Manchester Geol. Soc, vol. xv., pt. 
5, pp. 90-112. 
29 Fourth Report ... on the Circulation of Underground 
Waters, etc. [Doncaster, p. 31]. Rep. Brit. Assoc. for 
1878, pp. 382-419. 
30 Pervious Rocks of England and Wales. [Yorkshire 
noted]. Journ. Soc. Arts., vol. xxvii., pp. 811, 812. 
31 Etheridge, R., Junr. — Notes on the Bivalves contained 
