48 THE ENTOMOLOGIST. 



flattening, the thickening, &c., characteristic of their congeners. 

 By the way, the pupa-case of suhsericeata is superficially very 

 different from all the others which I have, whether of Lcptomeris 

 or Ptychopoda ; but I have made no close examination of them. 



A few words in conclusion as to the distribution of the 

 species of " Acidalia.'" I have remarked, in connection with 

 the larvae, how extremely local they generally are, and a study 

 of our British species will afford plenty of illustrations. We 

 have one species confined, in these islands, to Lewes, one to 

 Freshwater (Isle of Wight), one almost to Deal, one to Folke- 

 stone, one to the " Breck Sand " district of Norfolk and Suffolk, 

 one to the Isle of Portland, while others are only a little less 

 restricted in their range— e.^r., P. rusticata (which has colonies 

 in the Isle of Portland and in the Northfleet-Gravesend district, 

 but hardly occurs elsewhere), or P. contiguaria, which is confined 

 to the mountains of Wales. With the exception of this last, 

 and possibly the Breck Sands, each habitat which I have named 

 may reasonably be described as southern, and it should be added 

 that a few of the other species, though somewhat more widely dis- 

 tributed, are distinctively southern, others mainly so, while very 

 few of the species extend into Scotland. Our only characteristic 

 northern species of the group is Leptomeris {Pylarge) fmnata. 

 These facts shadow forth what no student of the Palasarctic 

 Geometrides as a whole can fail to notice — namely, that the 

 genus, or subfamily, belong more to southern Europe than to 

 northern. It has been my good fortune to have brought to me by 

 my kind friend Dr. Chapman four collections from different parts of 

 Spain, and one (some years ago) from Norway ; in all the former, 

 AcidaHid species were very much in evidence, generally indeed 

 forming the dominant family; whereas in the Norwegian collec- 

 tion, amongst a large number of species, there was only one of 

 them {L.fumata). In Staudinger and Rebel's ' Catalogue of the 

 Palaearctic Lepidoptera,' the genus is credited with 179 species, 

 of which we in Britain can claim 27, or about one-seventh. The 

 total number of Geometrides is given as 1229, of which Britain 

 yields about 275, or well over one-fifth. The discrepancy is 

 fairly marked, and would be still greater were it not for the 

 number of species which just maintain themselves in one spot 

 in our southern counties (chiefly on the coast). These species 

 will give much food for reflection to the student of geographical 

 distribution, and I regret that I have no definite suggestions to 

 offer on the subject. I trust I have said enough this evening to 

 show that, both in this and in other directions, the homely little 

 "wave moths" are not unworthy of the attention of the scientific 

 naturalist. 



