Rev. F. 1). Morice's Notes on Australian Sawflies. 301 



Note 1 .— On the Distribution of Sawflies in general : the three 

 Zoological " Realms " : and the probable origin of the 

 Australian Sawflies. 



J n this Note, and several of those which follow it, I 

 propose to avail myself on occasion of certain terms which 

 have been employed by Lydekker in his valuable and 

 suggestive little book A Geographical History of Mammals 

 (Cambridge Geographical Series, 1896). The principal 

 land areas of the Earth are there divided into three 

 chief zoological " Realms," namely, Arctogaea (= North 

 Land), Notogaea (= South Land), and Neogaea 

 (= New Land), and the two first of these " Realms " are 

 further divided into areas called " Regions." Though 

 originally founded on the Distributions of past and present 

 Vertebrate groups, especially Birds and Mammals, and 

 entirely without regard to that of Insects, these divisions 

 seem applicable also to the present Distributions of Sawflies. 

 Of their former Distributions we know, unfortunately, next 

 to nothing. Such fossil remains of the Sub-order as have 

 yet been described, are too few, too imperfect, and of far too 

 recent date, to throw any considerable light upon the subject. 



For our present purpose the limits of the three great 

 " Realms " will be sufficiently defined by saying that 

 " Neogaea " is nearly coextensive with such parts of 

 America as lie south of the Tropic of Cancer; " Arctogaea," 

 besides including the rest of America, extends across the 

 Bering Straits and occupies all Europe, Asia and Africa 

 with their adjacent islands, except so much of the Malayan 

 Archipelago as lies east of " Wallace's Line " ; while 

 " Notogaea " consists primarily of Australia and Tasmania, 

 which form a " Region " by themselves, but is also reckoned 

 as embracing three other isolated Regions, namely, (I) 

 the " Austro-Malayan " islands (especially New Guinea), 

 (2) Hawaii (the Sandwich Islands) and (3) " Polynesia " 

 (New Zealand, etc.). Hawaii and Polynesia, however, may 

 here be left out of account, for the former (as I learn from 

 Mr. Muir) has no indigenous Sawflies at all, and, with one 

 doubtful exception, the same is the case with Polynesia. 

 The Sawflies of New Guinea, Celebes, etc., are very little 

 known as yet, bul sonic of them appear to be related to 

 Australian forms, though not actually identical with them. 



Not much need be said I iere as to most of the " Regions " 

 included in Arctogaea. The largest and by far the most 



