220 PERCY SLADEN TRUST EXPEDITION 



Some of the very widespread species are probably either recent immigrants, or 

 introduced by human agency. For example, Ajihodius lividus, Aphodius nigritus, 

 A t annus f rater, and Rhyssemus ritsemce are (as far as my experience goes) only found 

 in the low cultivated country, feeding on the excreta of domestic animals : but under 

 purely natural conditions there would have been no such excreta for them to feed on in 

 the islands. Adoretun ivrsutus also is chiefly found in gardens near the coast, among rose- 

 bushes (on which it feeds) and other totally non-indigenous vegetation. 



B. Aldabra Group. The Lamellicornia consist of 7 species. Of these, Figidus 

 striatus is a Madagascar-Mascarene species, found also in the Seychelles, though repre- 

 sented there by a distinct variety ; the specimens from Aldabra are of the typical 

 Mascarene form. Phaocroiis im^ularis, originally described from Aldabra, has since been 

 recorded from Madagascar. Temnorrhynchus truncatus and Comaserica g ranidipennis 

 are both Madagascar species, the latter belonging to a genus which is confined to 

 Madagascar. The genus Lonchotus is also confined to Madagascar with the exception of 

 Lonchotus astovensis, known only from Astove Island and not (hitherto) from Madagascar 

 itself Lastly, the 2 species of Cetoniini are both allied to African forms. Mauso- 

 k'0])sis aldabrcmsis has actually been found in Wasin Island on the coast of British East 

 Africa, and it is so closely related to Mausoleopsis selika Raftray that it has been con- 

 sidered by Kolbe to be merely a variety of that species. Oxythyrea aldabrensis is allied 

 to a South African species [Oxythyrea marginalis Swartz) : Oxythyrea has representatives 

 in Madagascar, the Comoros, and Glorioso Island. 



Thus, the Aldabra Lamellicorn-fauna is entirely distinct from that of the Seychelles : 

 its strongest afiinities are with Madagascar, as might be expected from the proximity of 

 that country : but it contains an African element in the shape of the two Cetoniini. 3 of 

 the forms, however, — ^the two Cetoniines and the Lonchotus — are specifically distinct ; but 

 one of these [Mausoleopsis) is known to be not entirely confined to the Aldabra group, 

 while there is the possibility that the other two may be found outside those islands. 



The distribution of Cetoniini among the groups of islands visited by the Expedition 

 is interesting. The 4 species appear to fall into two little sets of 2 species each. On the 

 one hand, in the Northernmost and Northeasternmost groups, the Amirantes, Seychelles, 

 and Chagos, are two South- Asiatic species [Oxycetonia versicolor and Protcetia auri- 

 chalcea), which also extend into the Mascarene Islands and Madagascar. On the other 

 hand, in the South westernmost of the islands, those of the Aldabra Group, are two species 

 of strongly African affinities. In the Farquhar Group of islands the two sets of species 

 meet, for specimens of both the South-Asiatic Oxycetonia versicolor and of the African 

 Mausoleop>sis aldabrensis have been found there. 



Condition of the wings. This has been investigated in many of the species of 

 Lamellicornia, and in no case has any trace of reduction or atrophy of these organs been 

 found. 



