268 PROCEEDINGS OF SECTION D. 



two sub-orders, each of which contains two families. The first sub- 

 order, the Entotrophi, have the mouth-parts retracted within the head. 

 The family Campodeadse contains the single species Campodea 

 fragilis. Though plentiful throughout Europe and North America in 

 damp soil under stones, it is not known outside the Holarctic region. 



The Japygidse, with the single genus Ja^yx containing numerous 

 species, have been described from North and South America, Africa, 

 Europe, Southern Asia, and Western Australia. I have not yet met 

 with Japyx longiseta, Silv., the local species. 



The Ectotrophi, or sub-order of Thysanura whose mouth-parts 

 are not retracted within the head, are much more numerous than the 

 other sub-order. They are separated into two families, Lepismatidae 

 and Machilidse. The former, or Silver-fish, are divided into sixteen 

 genera, of which seven have been recorded from Western AustraUa. 



Silver-fish occur in the open under bark or fallen branches or 

 stones, but a considerable number are myrmecophilous, only living in 

 ants' nests, a smaller number live in the nests of termites, and a few 

 seem to be restricted to human habitations. 



Of a total number of 81 species, 44 are free-living, or their habitat 

 is unknown. (I have grouped these together since when specimens 

 have been taken from ants' nests or human habitations the fact 

 would generally be recorded.) Of the remainder, 24 species are 

 myrmecophilous, 5 termitophilous, and 8 anthropophilous, if I may 

 use this term for those only found in human habitations. 



Of the Anthropophiles several have become very widely spread 

 over the world, and it is difficult to judge where was their original 

 home. Our common species in Australia is Ctenolepisma longicaudata, 

 Esch., which is very widely distributed in houses in Africa. Since 

 several other species of the genus occur in Africa but none are known 

 from Australia, it is probable that our pest was introduced from the 

 Cape in early days, thus forming a parallel with the numerous South 

 African weeds which have taken such a hold on this continent. 



Another anthropophilous species, Thermobia domestica, Packard, 

 supposed to belong to Southern Europe, was also met with in Western 

 Australia by the Hamburg expedition. It is a blind species which 

 appears to live oi crumbs and starchy food, like the European silver- 

 fish, Lopisma saccharina, and neither of them do any real harm in 

 houses. Thermobia domestica has spread to North America and parts 

 of Asia, besides Australia. 



Of the five genera, which, since their members are free living, 

 we must presume are natives of Australia, Heterolepisma is the largest, 

 with four species. The genus is represented by two species in South 

 America. 



Of the genus Acrotelsa, two species are known from Australia ; 

 ore from the south-west, the other from the neighbourhood of Sharks 



