ccxviii FAUNA HAWAIIENSIS 



is perhaps the most variable, as it is also the most numerous, and it is the most isolated 

 structurally. In wet places the pronotum of this species is often quite white from a 

 dense growth of fungus on that part, but this growth seems in no way to injure the 

 insect. The arboreal species are a good deal hunted by the endemic birds, which seek 

 them beneath the bark, as well as on the foliage. That most local of Drepanid birds, 

 Viridonia sagittii-ostris, was almost always found to contain abundant remains of 

 P. freycinetiae, which it procures from the base of the leaves of Freycinetia. The 

 terrestrial P. pacificiim is the least powerful in jumping, the saltatory powers of the 

 arboreal species, when adult, being really prodigious for their size. It may be supposed 

 that since these so often lose the protective colour of their nymphs, they find sufficient 

 protection in their powers of leaping, when they have reached maturity. At any rate 

 the sudden change from a green insect to a black and orange one, as seen in P. atro- 

 femiginmim, is quite remarkable. All the species, as adults, are quite wingless, the 

 tegmina alone remaining as stridulating organs. Until the last ecdysis, wings and 

 tegmina A.q.vAo'^ pari passu, but at that ecdysis the tegmina undergo much further 

 special development, while the wing-rudiments, instead of proceeding with their develop- 

 ment, entirely abort. It is not known whether these crickets are subject to insect 

 parasites, but it is possible that the eggs will be found to be attacked either by the 

 Mymarid, Polyiiettia, or the Proctotrypid, Anteris. Not very infrequently they are 

 found to be infested by a parasitic worm (^Goj'dius) which emerges from the thorax or 

 abdomen, and is still more frequently seen at large on fronds of ferns or on other low 

 plants that grow in the damp shady places most affected by these little crickets. 



The rest of the endemic Grylloids form the most interesting part of the ortho- 

 pterous fauna. There are nearly a score of species known and they are distributed in 

 four genera, closely related to one another, forming together a natural group. Two of 

 the genera are represented by only a single species, and these are clearly offshoots from 

 each one of the larger genera. 



Nesogryllus, once characterized as distinct, has now long been known to us as the 

 male of Prognathogryllus, originally founded on the female sex only. The species of 

 Prognathogrylhis have well developed tegmina in the ^, adapted for stridulating, but 

 both sexes are flightless, the wings being rudimentary. 



In Leptogryllus and its offshoot 'fhaiiinatogrylhts, the wings are absent and in 

 some species the tegmina are so minute as to be only visible at the extreme sides of the 

 mesonotum, while in others they cover the whole (or almost the whole) metanotum, this 

 being the maximum of their development in the genus. Aphonogryllus is very imper- 

 fectly known and may be only an immature stage of some species of PrognatJiogryllus. 

 If not, it is clearly a derivative from the latter genus. 



All the species of Prognathogryllidae are entirely nocturnal and we have several 

 times found them at night running on the trunks of trees. In the daytime some of 

 them conceal themselves beneath bark, or in holes in decayed wood, while others inhabit 



