Marshall. — 0?i Dodonidia helmsi. 313 



in previous summers whilst making botanical and entomo- 

 logical collections, I have never previously seen any specimens 

 of this butterfly. Mr. Drew, curator, Wanganui Museum, 

 assures me that, though he has often shot over these gullies, 

 he has never seen any specimens of the buttei-fly. 



We were, unfortunately, unable to find any larvae or pupae 

 of the insect, but from the way the imago hovers over Brachy- 

 glottis repanda and Fuchsia excorticata it would seem pro- 

 bable that the larvae feed on the foliage of one of these trees. 



The occurrence of this butterfly suddenly, and in consider- 

 able numbers, seems to me a good instance of the sudden 

 sporadic increase of butterflies about which so much specula- 

 tion has been indulged in and so little is really known. In 

 1894 the usually rare Danais archiypus became abundant in 

 Wanganui, breeding in hundreds on plants of a species of 

 Gomphocarpus ; but, though the same plants have been kept 

 in the same place in gardens, and numerous others have been 

 sown, the insect did not appear last summer. The only cause 

 one can imagine to have effect in this peculiar circumstance 

 is the variation in climate and temperature from year to year. 

 It is possible that some peculiar and unusual conditions of 

 temperature or other meteorological variations are necessary 

 for its full development in any summer. 



Four of the specimens caught have been kept by my 

 brother and myself in private collections ; two have been 

 placed in the Wanganui Museum, and two in the Canterbury 

 Museum. The type-specimen described by Mr. Fereday is 

 also in the Canterbury Museum. For a full description of the 

 imago I refer to Mr. Fereday's article, " Transactions of the 

 New Zealand Institute," vol. xv., p. 193. 



In his description of the butterfly Mr. Fereday places a 

 note of interrogation after the genus, subsequently remarking 

 that, as he could not obtain the necessary books of reference, 

 he was unable to determine the genus. The specimen was 

 afterwards sent to England, and placed in the genus Dodo- 

 nidia ; but I have been unable to find the characters of this 

 genus in any of the reference works at my disposal. It 

 appears to be closely allied to the genus Dodona, which con- 

 tains a few Indian species. In that case it would belong to 

 the family ErycinnidcE, and not to the ISymphalidcB. 



EXPLANATION OF PLATE XV. 



Pig. 1. Dodonidia helmsi, upper side. 

 Fig. 2. Dodonidia helmsi, under side. 

 Fig. 3. Venation of primary. 

 Pig. 4. Venation of secondary. 



