284 Proceedings of the Boyal Physical Society. 



istic of the earthworm fauna of both these regions is the 

 abundance and prevalence of Lumbricus and Allolohophora, 

 amounting to an identity of species. These facts therefore 

 support the reasonableness of instituting an Arctogaea or 

 Holarctic region, as it is termed by Heilprinn. The com- 

 munity of the earthworm fauna of the northern parts of the 

 old and new worlds is of course explicable on the assumption 

 of a recent land connection. The distribution of certain 

 other animals (e.g., the glutton, beaver, and elk) is in harmony 

 with such a view, and there is no difficulty on the geological 

 side of assuming such a connection by way of Behring 

 Strait where the sea is shallow, and the distance from shore 

 to shore small. 



Dr Giinther noticed that Japan differs more particularly 

 than any other tract of country from the rest of the Palse- 

 arctic region, and resembles the Oriental. 



We have already seen that in Japan (and possibly ad- 

 jacent parts of China) alone is the genus Perichceta probably 

 indigenous. Here, then, is a decided confirmation of Dr 

 Glinther's position. 



Huxley proposed to separate New Zealand as a distinct 

 region, while Heilprinn distinguishes a Polynesian region 

 not including New Zealand. Is there anything to be said 

 for either of these modifications of Mr Sclater's regions ? 

 "We know too little of the earthworm fauna of Polynesia to 

 make any deductions worth putting on paper ; but New 

 Zealand is better known.^ It does not show a close re- 

 semblance to Australia. The prevailing genus in New 

 Zealand is Acanthodrilus, which is there represented by five 

 species. This genus is certainly not common in Australia ; 

 in fact only one species, A. australis, has been as yet met 

 with. And we have the careful investigations of Pletcher^ 

 for reference, which must comprise a fair sample of the earth- 

 worm fauna of South- Western Australia — the nearest part to 

 New Zealand. On the other hand, our knowledge of the 

 earthworm fauna of New Zealand is confined to that of the 



1 The Oligochsetous Fauna of New Zealand— P. Z. S. (1889), p. 377. 



2 Notes on Australian Earthworms — a series of papers in Proc. Lin. Soc. 

 N.S.W. (1886-89). 



