210 PROCEEDINGS OF THE ACADEMY OF [1883. 



peculiar groups than the tropical areas, because they have been 

 recently subjected to great extremes of climate,' does not affect 

 the present issue, seeing that the peculiarity is greatly increased 

 by uniting the two regions in question ; nor does it directly affect 

 the question of the Nearctic-Palaearctic relationship. 



" The second part of my paper deals with the examination of 

 the reptilian and amphibian faunas, and the general conclusion 

 arrived at is: 'That by the community of its mammalian, 

 batrachian and reptilian cliaracters, the Nearctic fauna (exclu- 

 ding therefrom the local faunas of the Sonoran and Lower Cali- 

 forhian subregions. which are Neotropical) is shown to be of a 

 distinctively Old World type, and to be indissolubly linked to 

 the Palsearctic (of which it forms only a lateral extension).' 

 Towards this conclusion, which, it is claimed, is also borne out 

 b}'^ the land and fresh-water mollusca and the butterflies among 

 insects, I am now happy to add the further testimony of Mr. 

 Wallace (overlooked when preparing my article) respecting the 

 Coleoptera ('Distribution,' ' Encycl. Britann.,' 9th ed., vii, 

 p. 274). 



"As regards the name ' Triarctic,' by which I intended to 

 designate the combined Nearctic and Palaearctic regions, and 

 which may or may not be ' somewhat awkward,' I beg to state 

 that, at the suggestion of Prof. Alfred Newton (who, as he 

 informs me, has arrived from a study of the bird faunas at con- 

 elusions approximately identical with ni}- own), it has been 

 replaced by 'Holarctic' In conclusion, I would say that, while 

 the views enunciated in my paper may not meet with general 

 acceptance at the hands of naturalists, it is to be hoped that they 

 will not be rejected because they may ' open up questions as 

 regards the remaining regions which it will not be easy to set at 

 rest.' "Angelo Heilprin, 



^^ Academy of Natural Sciences, Philadelphia, Apiil 6." 



In the issue of Nature for June 7, Prof. Theodore Gill, in an 

 article entitled " The Northern Zoogeographical Regions," submits 

 the following criticisms on my paper supplementary to those of 

 Mr. Wallace : — 



" The facts of zoogeography' are so involved, and often appar- 

 ently contradictory, that a skilful dialectician with the requisite 

 knowledge can make a plausible argument for antithetical postu- 



