";;36 ■ ■ INSECTS OF SAMOA. 



are not known to occur outside the Samoan Islands. This may to some extent 

 be due to the very insufficient state of our knowledge of the insects of other 

 Polynesian islands, but it can scarcely be doubted that each group of islands^ 

 if not each island, has many beetles peculiar to itself. The affinities with dis- 

 tant regions apparently indicated by the study of the present collections would 

 perhaps be rendered less striking by fuller knowledge of the faunas of the other 

 island groups. For example, five minute insects here recorded, Sacium 

 angusticoUe, Psammioecus pallidipennis, Litargus vestitus, Propalticus ocuJatus 

 and OrjyJiinus terminalis, have been previously reported only from the Hawaiian 

 Islands. Until it is known in what other islands these may also be found, it 

 would no doubt be possible to attach too great importance to this seemingly 

 remarkable distribution. 



Certain indications of American influence must also be mentioned. 

 The occurrence of a single example of Tenebroides mordax, a species only found 

 previously in Costa Rica, might have been regarded as accidental had it been 

 unaccompanied by any other facts pointing in the same direction ; but no 

 suspicion can be attached to the Aphodiid Ataenius orbicularis, numerous 

 specimens of which have been taken by various collectors, and which, originally 

 described as peculiar to Samoa, has since been found to be a Central American 

 species. Again, Hystricones vagans, an insect of minute size but with well-marked 

 generic features, here described and figured for the first time, is attributed to a 

 genus of which the only other known species is found in Central America. Two 

 other species which also make their first appearance here, Colydodes samoensis 

 and C. denudatus, similarly belong to a Tropical American genus. A single 

 species of this genus was long ago recorded from Mysol. Of the same significance 

 is a newly described species of Hapalijjs, a genus almost peculiar to Tropical 

 America, but of which one species is known to occur in New Zealand and one 

 in Ceylon, while three are found in the Madagascan region. 



The only new genus that I have considered it necessary to describe is of 

 interest from the standpoint of geographical distribution, as it includes, in 

 addition to Monothallis samoensis, found in the Samoan, Fijian and Loyalty 

 Islands, a species inhabiting Gilolo and another occurring in Australia, all 

 distinguished by the possession of a particular structure for stridulation ; this is 

 situated on the head, and is of a type not found in their allies. The new genus 

 is not alone in showing Australian affinities, but the latter are rather with the 

 Papuan element in the Australian fauna than with the truly Austrahan 



