500 S. E. Peal— Selenology. 



banished to the Mecllterranean. Other shells of equal interest could 

 be added, but space forbids. 



How shall we interpret these facts? Are they best explained by 

 supposing the shells to have inhabited a sea whicli had, albeit over 

 200 fathoms deep, no deep-water fauna at all, which nowhere left 

 a shell -bank or even a group of shells on the spot where they lived 

 (on this point Gwyn Jeffreys and Mr. R. D. Darl)ishire spoke very 

 explicitly), which mingled shells of the most diverse habitat and 

 left shells at present confined to shallow water and a sandy bottom 

 in the muds of its profoundest deptlis, a sea which pertinaciously 

 avoided the deep gulfs between the tiny islets that studded its 

 sui'face, and that finally retired without leaving beach, shore- 

 platform, or so much as a cliff or sea-worn cave behind to mark 

 its former extension. 



Or, do not the facts harmonize better with the view, so strongly 

 supported by the physical indications, that the ice-sheet, whose 

 extension over the district and in the direction I postulate is 

 admitted by Mr. Eeade,' having advanced over the Irish Sea, bore 

 along involved in its mass or in its ground-moraine portions of the 

 vast banks of shells with which that, then as now, shallow sea was 

 cumbered, and mixed up the mangled remains, not only of the but- 

 recently-vacated boreal forms, but also of the warm-water species 

 which lived in the preceding Pliocene Period. 



In conclusion I would remark that it is before all things necessary, 

 in the discussion of the question of the condition of Britain during 

 the Glacial Period, to take a pretty wide survey of the countiy, and 

 to try and bring all the facts into a single coup iVoeil. The former 

 Mr. Keade has certainly done, as witness his papers on the Drift of 

 Cromer and Yorkshire ; but the latter I fear he has not attempted, 

 else we should hear less of the significance of the fact that Three 

 Eock Mountain, Moel Tryfaen, Gloppa, and Macclesfield are at 

 about the same altitude and on the same parallel of latitude. Let 

 Mr. Eeade look 20 or 30 miles E. and W. of his terminals and see 

 in what way his great submergence declined. 



I have touched but upon the fringe of a great subject, and must 

 leave the publication of a more general statement of my views till 

 the autumn, when Prof. G. F. Wright's new volume in the Inter- 

 national Scientific Series, to which I have contributed a chapter, 

 will be out. In the nieantime Mr. Eeade will, I hope, deal with 

 some of the topics which I suggested at the outset. 



VI. — Selenology. 



By S. E. Peal, Esq. 



AS one who has for many years made a special study of the lunar 

 surface, and who is thoroughly convinced that the geologist 

 alone can now extricate selenology from the slough in which it 

 has hopelessly stuck fast, I venture very briefly to lay the case 

 before your readers, in the hope that some one will come forward 

 and help us. 



^ See his papers in the Q. J.G.S., and " Nature," vol. xl. p. 247. 



