ORTMANN : TERTIARY INVERTEBRATES. 319 



tively shallow sea, where there is now deep water, and when we make 

 this assumption, there is no difficulty in constructing a continental connection 

 of the same parts, as soon as other lines of evidence force us to do so. 



This communication of the Patagonian seas with Antarctica through 

 shallow water persisted through a large part of the Tertiary, probably 

 almost up to the recent time. V. Ihering has already assumed a repeated 

 and continuous immigration of marine Antarctic forms into the South 

 American literal (v. Ihering, especially 1897 b, pp. 532 and 533), and there 

 is no reason to reject this theory. That during Tertiary times a direct 

 communication was present with the nearest parts of Antarctica, is quite 

 probable after the discovery of marine fossils on Seymour Island, Dirck 

 Gherritz Archipelago (Graham Land). The fossils found there, especially 

 the presence of a species of Cucullcea, strongly suggest Patagonian beds 1 ). 



2. RELATIONS OF THE PATAGONIAN DEPOSITS TO 



OTHER PARTS OF SOUTH AMERICA, AND TO 



THE REST OF THE WORLD; THEORY OF 



"ARCHIPLATA" AND "ARCHHELENIS." 



We have seen above that the most characteristic feature of the Pata- 

 gonian fauna is the dissimilarity to other faunas of about the same age, 

 the resemblance to the Antarctic faunas of Australia and New Zealand 



1 It may be well to state here the facts about these Tertiary fossils, since they have been re- 

 peatedly mentioned lately, but without proper quotations, so that it is difficult to keep track of 

 the literature. 



These fossils were collected in the season 1 892-3 on Seymour Island, Dirck Gherritz Archi- 

 pelago (northeast of Graham Land) in 64 24' S. Lat, by Captain Larsen of the "Jason," and 

 given to Dr. C. W. Donald of the " Active," who brought them back to Scotland. Dr. J. Mur- 

 ray was the first to notice them in the Geographical Journal, vol. 3, January, 1894, p. 1 1, foot- 

 note, and he says that according to Messrs. G. Sharman and E. T. Newton, of the Geological 

 Survey, they belong to the genera Citcull&a, Cytherea, and Natica (besides pieces of Coniferous 

 wood). He points to the probable Tertiary character of them, and compares them with lower 

 Tertiary fossils of England and Patagonia, which would especially refer to the Cucullaa. 



Dr. Murray again refers to these fossils in the Scottish Geographical Magazine, vol. 10, April, 

 1894, p. 195, and they are also mentioned in Peterson's report on Captain Larsen's discoveries 

 (Peterson, Die Reisen des " Jason " und der " Hertha," in : Mitteilungen der Geographischen 

 Gesellschaft in Hamburg. 1891-92. 1895, p. 273). Again they have been mentioned by 

 Hedley(i89S, p. 7), by Heilprin (Science, Febr. 28, 1896, p. 306), by Ohlin (Ymer, 1898, h. 4, 

 p. 301), and by Fricker (1900, p. 182), but with insufficient and partly incorrect quotations. 



