188 ANNALS NEW YORK \('M)r:\IY OF SCIENCES 



taiiilv less so tlian tlic N('(»ti'()|)ic;il rc«iion. Tlu' .Maliigasy subregion is 

 related not to tlie inodtTii Inii to the Tertiarv Ethiopian region; its sup- 

 posed Oriental affinities will be considered later. 



The Neotropical region is connected with the ty|)ical TTolarctic through 

 the Sonoran, as the Ethiopian is tiirough the Mediterranean intiTme- 

 diates ; but the relationshii) is more remote. During the Tertiary, the 

 region was much more distinct than it is now. 



In considering the records of past faunae of one or another of these 

 regions as a guide to the dispersal of different groups, it is very necessary 

 to remeniher that our records are oft(Mi chiefly oi- wholly from a small 

 part of the region, often far from t\|)ieal. 



Our knowledge of i'akearctic fauna' in the early Ti-rtiary is wholly 

 from western Europe, an outlying, marginal part, more or less submerged 

 and archipelagic. Its relations to the main hody of Pahearctic land life 

 were probably much like those of the East Indian archipelago to the 

 continental portion of the Oriental region. In the later Tertiary and 

 Quaternary, we obtain a broader outlook on tlte Pakiearctic fauna, but 

 even then it is incomplete. 



In the Oriental region, we know nothing of the land life of the early 

 Tertiary, and in the later Tertiary we know only the life of its northern 

 borders, close to the Pala^arc^ic region and doubtless more nearly approxi- 

 mating the Pala-arctic fauna then than now, as the Himalayan barrier 

 was less complete. 



The result of these two facts will apparently be that the early Tertiary 

 Palaearctic fauna will appear by the record to ho less progressive than it 

 really was and that the Tertiary Oriental fatma will ap])ear to be more 

 progressive than it really was. In the Nearctic Tertiary, the record is 

 chiefly confined to the Western plains; we know little of the Canadian 

 Nearctic — presumably more progressive. In the forested regions of the 

 East and South, where we might expect to find primitive survivals, or on 

 the Pacific coast, where we might expect to see stronger Pala?arctic influ- 

 ence, our knowledge is very imperfect, although the few available data 

 are in conformity with a priori deductions. 



in the Neotropical region, our chief dependence is upon tlic Argentine 

 fauna' which should be both the most progressive and least influenced by 

 Northern immigration. 



In the Ethio])ian region, we have but a single glimpse of the Tertiary 

 land fauna, and that is derived from Egypt, where we might expect to 

 find a transitional fauna, combining true Ethiopian autochthones with 

 immigrants from Palaearctic or northwestern Oriental fauna'. But, since 

 the water barriers to the north of Egypt wei-c more extensive and the 



