^12 I'HE ENTOMOLOGISI'. 



seasons when most Lepidoptera were unusually numerous. The 

 gist of my own paper more especially dealt with the subject on 

 broad principles, and I explained one cause which unquestionably 

 produced the great abundance of many species of Lepidoptera 

 last season in New Zealand. In his original paper Mr. Adkin 

 enumerates over a dozen species which appear sporadically in 

 the British Islands, and after discussing the evidence of such, 

 concludes, " however incomplete it may be, tends to the conclusion 

 that immigration is a chief factor in the causes of great abundance 

 occasionally observed, and in some instances the direct and only 

 cause." Eeferring to my remark that immigration could have 

 no bearing on the question in New Zealand, Mr. Adkin says, " I 

 cannot admit that this greater distance would form an insur- 

 mountable obstacle to immigration ; if it were so, it seems highly 

 improbable that that essentially New World species, Anosia 

 plexippus, would have reached Great Britain ; and except for this 

 greater sea space, the relative position of the British Islands and 

 New Zealand to their respective Continental bases are singularly 

 alike," and adds, " That migrations of Lepidoptera from the 

 Continental portion of the European area to the British Islands 

 do occur has already been shown, and is it not reasonable to 

 suppose that a similar condition of things exists in regard to 

 New Zealand ? " Let us briefly consider these remarks. The 

 dispersion of Anosia plexippus in late years over the greater part 

 of the known world presents an interesting problem, which, when 

 perfectly solved, should explain many of the apparent anomalies 

 in the geographical distribution of Lepidoptera. I am not well 

 versed in the literature of the subject, at least so far as it deals 

 with the modes of dispersion of this species. But its occurrence 

 at the Antipodes is even more remarkable than in the British 

 Islands. It was first captured in New Zealand by Mr. F. W. 

 Sturm, up the Wairoa Eiver, Hawkes Bay, North Island, in 

 December, 1840, and subsequently on the Eangitikei Eiver, on the 

 western side of the Island. It was also obtained in Westland, 

 South Island, by Sir James Hector, nearly thirty years ago ; and 

 I observed it on the Eangitata Eiver, on the eastern side of the 

 Island, thirteen years ago. But I have not heard of a single 

 capture for many years past. I will here refer to other species 

 formerly inhabiting New Zealand, but now extinct, as I desire to 

 adduce evidence to show that these species were probably ancient 

 inhabitants of the Islands, and not in all cases mere modern 

 accidental introductions by man. A male of Catopsilia catilla 

 was taken many years ago in the grounds of St. John's College, 

 Auckland, and is now preserved in the local museum. Several 

 specimens of the beautiful Diadema nerina were captured forty 

 years ago, and sent at that time to the British Museum by the 

 late Dr. Sinclair, of Auckland, and others taken and observed by 

 the late Eev. Eichard Taylor, of Wanganni, and Dr. Barker, of 



