128 Mr. E. Meyrick on the 



exceptions occur, doubtful cases being decided by 

 majority of characters. When, however, they are dis- 

 tinguished by a single point (as, for example, the Depres- 

 sariidce and (Ecophoridce differ by the presence or absence 

 of ciliations of the antennae of the male), this character 

 admits of no exception. It will be apparent that this is 

 in accordance with what might be expected to result from 

 the natural formation of families ; for supposing, by 

 variation of a particular character and extinction of 

 intermediate forms, a new and distinct family type to be 

 brought into being, there will be no reason whatever why 

 the new family should not exceptionally, whether by 

 reversion or independent variation, develop again solitary 

 instances of the special character of its parent family. 

 If it does this to any considerable extent the family can 

 no longer be maintained ; but if it does it in rare in- 

 stances only, and at the same time continues to diverge 

 also in other respects, it is probable that by a considera- 

 tion of all points combined there will be no difficulty in 

 detecting the true position of any particular genus, and 

 such real or apparent reversion to any ancestral type 

 need not be taken to vitiate the genuine distinctness of 

 the family. 



It remains to sketch the probable process of develop- 

 ment of the group, according to this scheme of classi- 

 fication. The origin of the whole is to be sought in the 

 (Ecophoridce, which represent the simplest type, them- 

 selves originating in the Butalid group of the Elachistidce 

 (the classification of which, whether as one or more 

 families, need not here concern us). In accordance with 

 this hypothesis, we find the (Ecophoridce at their maxi- 

 mum of development in the Australian region, which 

 from its isolation has always tended to preserve such 

 primitive forms from the disastrous competition of 

 superior types ; whilst in other regions they have been 

 in great part (but nowhere entirely) supplanted by later 

 developments. The (Ecophoridce were early divided into 

 two natural groups (above distinguished as A and B), in 

 the former of which vein 7 of the fore wings terminates 

 in the hind margin or apex, and in the latter in the 

 costa. From group B rose the Depressariidce, differing 

 by the loss of the characteristic ciliations of the antennae, 

 and originating from near Psecadia. From the same 

 group came also the Dasyceridce, a small but ancient 

 development from near (Ecophora. The Glyphipterygidce 



