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XV. On the classification of the Australian Pyralidina. 

 By E. Meyrick, B.A. 



[Read April 2nd, 1884,] 



The present instalment includes the Musotimidce, Boty- 

 dida, and Scopariadce, with some additional species of 

 the two families i^reviously treated. There remain the 

 Hydrocamjnda and Pterophoridce, which will form the 

 subject of a third paper ; and the Cjximbidce, Phycididce, 

 and Galleriadce, which have been already described 

 elsewhere. I think that this family subdivision will 

 allow of the development of the group being properly 

 understood. Its essential principle is, as I have explained 

 before, that one family is not bound to be absolutely 

 separated from another simply by the presence or 

 absence of a single character, but by a majority of 

 several distinguishing points ; which is the most that 

 can be expected from a system really arranged on 

 natural lines. 



It seems to me useless to attempt to judge of the 

 value of characters for classification, without strict 

 reference to the principles of evolution. I think it might 

 be laid down as an axiom, that when an organ has 

 wholly disappeared in a genus other genera which 

 originate as offshoots from this genus cannot regain the 

 organ, although they might develoj) a substitute for it. 

 Thus in the Geometrina we have a number of genera in 

 which the larvae have wholly lost three pairs of abdo- 

 minal legs, the character being proved to be very per- 

 sistent ; it must be held that no genera derived from any 

 of these could recover the lost pairs of legs, and there- 

 fore the Geometrid genera with 12-legged larvEe must be 

 ancestral types, and not derivative ; and for the same 

 reason the Geometrina must be regarded as a terminal 

 development, a group which ends in itself and has 

 given rise to no other groups. The character of the 

 absence of ocelli may be applied in the same way. So, 

 in the present group, the Botydidce are specially cha- 

 racterised by the absence of the uncus in the male 



TEANS. ENT. SOC. LOND. 1884. — PART III. (OCT.) 



