248 Transactions. 



Art. XV. — Revision of New Zealand Notodontina. 



By E. Metrics, B.A., F.K.S. 



Communicated by G. V. Hudson, F.E.S. 



[Received by Editors, 30th December, 1916 ; issued separately, 16th July, 1917.] 



I now complete my revision of the New Zealand Lepidoptera by dealing 

 with the Notodontina. This group is relatively more prominent in New 

 Zealand than elsewhere, being only surpassed in numbers by the Tineina. 

 It should be realized, however, that they are comparatively easy to collect, 

 calling in general for little skill or acumen ; so that the group is probably 

 better known than any other, and would, indeed, have been pretty well 

 exhausted before now if it were not that many species are strictly alpine 

 and very local, requiring to be visited in their special haunts. 



This group exhibits the same inequality of representation of families 

 that has been noticed in the others ; three-fourths of the whole number of 

 species belong to the family Hydriomenidae, which is very adequately re- 

 presented, whilst the Selidosemidae and Monocteniadae are very imperfectly 

 exhibited, and the other families either wholly absent or indicated only by 

 one or two casually introduced immigrants. Nearly all the local affinities 

 are with the South American region, in accordance with the principles laid 

 down in earlier papers of this series ; but the few Monocteniadae are mainly 

 related to Australian forms. 



I take the opportunity of explaining here why I am unable to accept 

 the proposal made by Mr. Prout, and communicated through Mr. Howes 

 (Proc. N.Z. Inst. vol. 44, p. 54), to establish a genus Larentia Treitschke 

 (whose name is disguised as Frietschke in the above communication) to 

 include those species of Xanthorhoe in which the hindwings have " vein 5 

 from below centre of discocellular, which is angled," since it may afford 

 a useful lesson in the principles of classification, a subject on which I hope 

 to be able to issue a more extended treatise some day. I will begin by ex- 

 plaining the nature of the structure referred to, using my own terminology. 



The posterior wall of the cell of the hindwings (between veins 4 and 6) 

 I call the " transverse vein." From about the centre of this, or rather above 

 it, a weak internal fold runs towards the base, representing an original internal 

 vein, and the junction of these usually coincides nearly with the lower end of 

 the dark discal spot ; the transverse vein is commonly more or less slightly 

 angled inwards at the point of junction, but may also be practically straight. 

 Now. in some species of Xanthorhoe vein 5 rises from the point of junction 

 mentioned above ; in others it rises from a more or less pronounced outward 

 angulation between this point and vein 4. Mr. Prout would keep the species 

 of the first category as Xanthorhoe, and separate from them those of the second 

 as Larentia, and the proposal sounds plausible. 



When I formulated my classification of the European species of this group 

 in 1892, on lines which have since met with general acceptance, I did not 

 overlook this variation in structure, but rejected it after examination as 

 unsuitable for use. Since that time, however, my available material has 



