cl FAUNA HAWAIIENSIS 



particular variety to predominate or become conspicuous. Some of the variations have 

 been figured in the systematic portion of this work. The Hawaiian species, Hke 

 others, rest during the daytime with outspread wings on the trunks of forest trees. 

 E. monticolans on various trees and E. craieinas on Acacia koa are very often obtained 

 by examining the trunks. The latter also rests on the surface of rocks. One or two 

 species are found above the elevation of the true forest-belt, and some are restricted 

 to very wet woods. E. monticolans has been bred from a full-grown larva found on 

 Metrosiderus polymoj'pha. The species of XanthorJioe appear to be all rare insects 

 in the imaginal state, and their earlier stages are not known. X. insularis is found 

 above the forest-belt on Haleakala, Maui, from seven or eight thousand feet above sea- 

 level upwards. The other three species are forest insects. Progonostola cremnopis, 

 forming an endemic genus, is widely distributed, and occurs on Oahu, as well as on the 

 windward islands. Near Honolulu it may be found resting on tree-trunks or the stems 

 of tree-ferns on Mt Tantalus, and on the decomposed lava of steep cliffs at Nuuanu 

 Pali. It bears a considerable superficial resemblance to Xanthorhoe caustoscia. The 

 single species of Dasyuris was found on the upper skirts of the forest on Haleakala, 

 Maui, where it occurs periodically in extraordinary numbers, flying by day. On several 

 visits to the locality not a single example has been observed, but on one occasion it was 

 swarming over a limited area. Though not a rapid flier, it was not very easily captured, 

 being expert at keeping just out of reach. The smaller Hydriomena aplioristis appears 

 to have similar habits, being also a day-flier, though also attracted by light at night, 

 but is usually seen singly, and we have never seen it in numbers. It has so far only 

 occurred on Hawaii. 



Selidosemidae. — The Selidosemidae with about forty known species, and, doubt- 

 less, others undiscovered, are a most important element of the Lepidopterous fauna. 

 Most of these are absorbed in the genus Scotorythra with 34 species, and the other 

 four genera may be looked on, for the most part, as merely more modified forms of the 

 large genus. All five genera are endemic. The forms included in Scotorythra itself 

 are of varied structure, as if tending to break up into several groups or genera, and 

 these distinctions in the adults appear to be to some extent correlated with corre- 

 sponding differences in larval characters. The smaller species of the genus, belonging 

 to the group of .S". corticea, for instance, have a characteristic appearance and pattern 

 (or form of the second line of the forewings), tending at the same time to differ in 

 character of neuration, and also in the length of the tibial spurs from the others. Some 

 of them, and perhaps all, rest at times with spread wings, Boarmia-like, on the trunks 

 of trees. On the other hand the numerous species, large and small, of the S. rara 

 group, rest, Anisopteryx-like, with the wings unspread, so as to form an elongate triangle, 

 creeping into holes in trees or beneath bark, or lying hidden amongst masses of dead 

 fern leaves during the daytime. Sisyrophyta is remarkable for the secondary sexual 



