4 



INSECTS OF SAMOA. 



but these very doubtful cases seem to be the only possible instances of mimicry 

 in the area. H. lutescens greatly resembles E. schmeltzi, but the two species 

 do not occur in the same islands. 



Distribution 



With the single exception of the comparatively recent American immigrant, 

 Danaida archippus, the butterflies inhabiting Samoa and the neighbouring 

 groups of islands are all Indo-Malayan in origin ; most of them call for little 

 note on the subject of distribution, being very wide-spread throughout the 

 islands of Polynesia. The majority of them seem to have reached Samoa by 

 way of Fiji, which is the Eastern limit of quite a number of species, but the cases 

 of Ewploea schmeltzi, Hypolimnas errabunda, and Atella exulans are different. 

 The first-named has no close relatives nearer than the Loyalty Isles, the other 

 two both find their closest allies in Papua (and in the case of H. errabunda in 

 the Solomons also), and have not been recorded in any form from the islands 

 intervening between these localities and Samoa (a distance of about 1,200 miles). 

 Many of these islands are not very well-known, and, since both H. errabunda 

 and A. exulans are mountain species, it is possible that they have been over- 

 looked, as they had been in Samoa, and that races of them will turn up in Fiji 

 and perhaps elsewhere ; but this argument does not apply to E. schmeltzi, which 

 is a coastal species and could not be overlooked in any locality where any col- 

 lecting at all has been done. A possible explanation of the absence of this 

 species from any locality between the Loyalties and Samoa is that it existed 

 there at one time, but has been worsted in the struggle for existence by the 

 larger and more vigorous E. eleutho, which feeds on the same food-plants and 

 would, therefore, come into competition with it. Though both species occur 

 in Samoa, they are confined to separate islands, and strong support to this 

 suggestion would be found if this should prove to be the state of affairs in the 

 Loyalties also. Unfortunately, the fact that the material available from the 

 latter group is insufficiently supplied with data makes the test impossible of 

 application at present. Neither H. errabunda nor E. schmeltzi is recorded in 

 any form from localities east of Samoa, but Atella gaberti, which appears to 

 be fairly closely related to A. exulans, occurs in Tahiti, though apparently not 

 in the intervening groups. 



The other point of special interest, in the distribution of the butterflies 



