CLAVICOEINIA AND LAMELLICOKNIA 



By Gilbert J. Arrow 

 (With 13 Text-figures.) 



In reviewing the beetles of many different families (over seventy species), the 

 identification of which has fallen to my share, the fact that calls for remark 

 in the first instance is the predominance of species breeding in rotting wood, 

 such as those belonging to the three families Cucujidae, Colydiidae and 

 LucANiDAE, of which nearly all those previously unknown are members. No 

 less than four species of Lucanidae (Stag-beetles), apparently peculiar to the 

 Samoan Islands, are recorded, while the other great Lamellicorn groups, so much 

 more numerous amongst the insect populations of most regions of the earth, 

 are either completely absent or represented only by species of very wide dis- 

 tribution, which may be supposed to have been introduced in comparatively 

 recent times, probably by human agency. The, in several cases, too successful 

 establishment of those immigTants, which have become serious pests, shows that 

 there are no local conditions inimical to their kind to account for the deficiency. 

 The explanation is probably to be found in the fact that while the Lucanidae 

 pass their early stages in rotting wood, the Scarabaeid Lamellicornia nearly 

 all do so underground, so that the ocean, which may have brought the former in 

 drifting logs from other shores, formed an impassable barrier to the latter, 

 until surmounted by human agencies. 



The four apparently indigenous species of Lucanidae have developed no 

 very strongly marked difJerential features, and, although suggesting a fairly 

 respectable antiquity for the fauna, do not afford ground for regarding it as 

 other than comparatively recent. 



As to the origins of the beetle-fauna, although some of the numerous widely- 

 distributed constituents, such as Adorelus versutus, Oryctes rhinoceros and 

 Oxycetonia versicolor, appear to have come from Asia, so far as can be judged 

 from this part of the fauna it owes very little to Asiatic elements. A consider- 

 able proportion of the species are completely cosmopolitan, but a fair number 



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