ccxx FAUNA HAWAIIENSIS 



species of this group appear nearly all to be confined each to one island only, though 

 Leptogi-yllus nigrolineatus has been found on Oahu and Maui and L. apicalis on 

 Molokai, Maui and Oahu, and it is possible that these two described species are really 

 only forms of one. L. forfictilaris occurs on Hawaii and in the western mountains 

 of Maui. 



Review of Thysanura and Collembola. 



Very few species of these interesting insects were observed by me in the islands, 

 and of these a single species oi Japyx, and two each of Lcpisma and Machilis only have 

 any claim to be considered indigenous. Campodea was only noticed in the mountains 

 in the vicinity of Honolulu, in the early years of my collecting, being generally found 

 in decaying stumps or beneath rotting logs. As it was subsequently noticed in the soil, 

 in which foreign plants were imported, there is no reason to doubt that the genus is an 

 importation. 



Japyx was only collected very rarely on Kauai, living beneath logs in company 

 with the earwig Anisolabis perkitisi [ = A. pacifica, huj. op. olim). Of the two species 

 of Machilis, M. heteropus is an abundant species in the forests and is found beneath 

 bark of trees, amongst dead adherent fronds of tree-ferns, and in rotten stumps. Indi- 

 viduals are very numerous and vary in their colour pattern. M. perkinsi was only 

 found on Kauai. 



Lepisma hawaiiensis is also only known from that island, where it was observed in 

 numbers under bark of forest trees. Another Lepisma occurs on rocks near the sea- 

 shore both on Oahu and Kauai. At least two species of the genus have been seen in 

 houses in Honolulu, where one at any rate is injurious to books and other articles. 

 Some minute Thysanura have been imported in earth containing ants' nests and are 

 now found established in the islands with these ants. One box of plants that I 

 examined a short time after its importation contained several ants' nests in the soil, and 

 many Thysanura infested the nests. 



It is quite uncertain whether there are any endemic Collembola in the Hawaiian 

 group, as they are frequently imported with plants, and many have become established 

 and very widely spread. In some forest localities we have noticed that they have 

 become much more numerous than was formerly the case, and this may be taken as 

 evidence in favour of their foreign origin. 



The single species of the Achoreutidae, Neanura citronella, was the only form 

 observed that struck me as likely to be endemic, since it was found beneath the bark of 

 native forest trees. 



