54 Prof. H. A. Nicholson — 07i Fossil Tubicolar Annelides. 



now. It would be a different matter indeed could we suppose the 

 Atlantic to have been obliterated at the same time as the Mediter- 

 ranean ! But under such geographical and physical conditions as 

 did actually obtain in north-western Europe during our local-glacier 

 period, it is quite clear that the summers in Britain must have been 

 miserably ungenial, and the vegetation poor and scantj^ The 

 Arctic sun, instead of shining as in Asia upon flat snowless plains, 

 would strike its rays in the extreme north of Europe over extensive 

 snow-fields, where all the heat would be taken up in melting the 

 snow, and consequently any wind that reached our latitudes from the 

 north would be cold and ungenial. 



In winter-time, supposing the Gulf-stream to have flowed then as 

 it flows now, the cold would be ameliorated over all western Europe. 

 But should the presence of the Gulf-stream be objected to, then, in 

 the absence of this great heat-bringer, our winters would indeed be 

 excessive, and our summers dreary in the extreme. In short, we 

 may conclude that so long as Europe exposes a vast line of coast to 

 the Atlantic, and so long as her physical features endure, just so 

 long will her climate continue to differ from that of either Asia 

 or North America, no matter whether or not the British Islands 

 become continental or the area of land in the Mediterranean basin 

 be increased. And as it is in the present, so also it must have been 

 in the past. No mere obliteration of our inland seas could neutralize 

 the influence of the outlying ocean. If the summers of Europe 

 are at present rendered less excessive by the presence of the 

 Atlantic, the same must have been the case during the last con- 

 tinental condition of our islands, and that to a much greater degree, 

 owing to the presence of more numerous and larger snow-fields. 

 For this, if for no other reason, it seems to me that the theory of 

 seasonal migrations during the Pleistocene period miast be abandoned. 



In illustration of Mr. Geikie's paper, see PI. IV. Fig. 1, Map of Europe, with 

 Isothermal lines of July, Eeduced from Dr. A. Petermann's Memoir on the Gulf 

 Stream, Geographische Mittheilungen, 1870. 



II. — Dksoeiptions of two New Species of Fossil Tubicolae 



Annelides. 

 By H. Allbynb Nicholson, M.D., D.Sc, M.A., F.R.S.E. 

 Professor of Natural History and Botany in University College, Toronto. 

 (PLATE IV. Figs. 2 and 3.) 



IN a recent paper (American Journal of Science and Arts, vol. iii., 

 March, 1872), I founded a new genus, under the name of 

 Conchicolites, for the reception of some singular Tubicolar Annelides 

 found growing upon the shells of Orthocerata in the Lower Silurian 

 of the North of England. The following were the characters which 

 I ascribed to the genus, and to the single species upon which it was 

 founded : 



CoNOHiooLiTES, Nich. — Animal social, inhabiting a calcareous (?) 

 tube, attached in clustered masses to some solid body. The tube 

 conical, slightly curved, attached by its smaller extremity. The 

 wall of the tube thin, its external surface devoid of longitudinal 

 strise. The tube thin, composed of short imbricated rings, but appa- 



