James Geikie — On Changes of Climate. 215 



As I am made jointlj'- responsible with Mr. Jeffreys for the addi- 

 tional species recorded in the lists, it may be proper here to state that 

 Mr. Jeffreys is the authority for the following species : Coralline 

 Crag, Cardium Norvegicum, Lima elliptica, Lutraria ohlonga, Modiola 

 discors, Psammobia costulata, Solecurtus antiquatus, Thracia distorta 

 Aclis, 3 sp., JEmarginida rosea, Murex acicidatus, Odostomia inscidpta, 

 Bissoa proxima. Eed Crag, Cardium nodosum, Panopea plicata, 

 Pholadomya papyracea, Dentalium abyssorum, Actceon escilis f Conop- 

 leura Maravigne? F. despectus, Menestho alhida, Bissoa striata, 

 Trochus Groenlandicus. 



How far variety extends is a matter of opinion, but A. exilis is 

 described by Mr. Jeffreys as having three whorls and A. Etheridgii 

 by myself as with 5-6. Conop. crassa is not the same as C. Mara- 

 vignce, if sculpture is any criterion, and with respect to Pleurotoma 

 attenuata, var. tenuicosta, it must be a very elastic variety indeed, if 

 it embraces all the distinctive marks of the species Mr. Jeffreys 

 assigns to it. When I requested Mr. Jeffreys' opinion upon the shells 

 in question, I suggested that one of them was P. attenuata ; on com- 

 parison with his figured specimen he thought not, and proposed the 

 name notata, which I afterwards adopted for one of my species. 



V. — On Changes of Climate during the Gtlacial Epoch. 



By James Geikie, F.E.S.E., 



District Surveyor of the Geological Survey of Scotland. 



(SixtJi Paper.) 



(Continued from the April Number, p. 170.) 



IT has already been sufficiently insisted that no warm or genial 

 climate has intervened since the close of the Glacial epoch. The 

 climate of Britain is milder now tlian at any other period subsequent 

 to the re-elevation of our country after the last great submergence ; 

 our winters have been gradually growing less intense ; Britain has 

 slowly passed from an Arctic to a temperate condition of things. 

 Mr, Dawkins accounts for the absence of the mammal-bearing drifts 

 in Scotland and the upland districts of England by supposing that 

 in post-glacial times all these regions were covered with snow and 

 ice. This, however, is a rather exaggerated picture of post-glacial 

 Britain. It is quite true that after the emergence of our country 

 from the last great subsidence, a few local glaciers continued to 

 linger on among our mountain valleys. But the Lowlands of 

 Scotland were most assuredly never again covered with glacier-ice. 

 In post-glacial times the low country of Scotland was just as free 

 from ice as the low grounds of England. And since the hippo- 

 potamus and his congeners do not occur in the post-glacial drifts 

 of Scotland, this must be owing to some very different cause than 

 that suggested by Mr. Dawkins. If the hippopotamus, the elephant, 

 the rhinoceros, the hyeena, the lion, the Machairodus, and others, really 

 lived in England during the post-glacial period, they cannot have 

 failed to occupy Scotland at the same time. Yet if they did so, 



