INTRODUCTION clxxxi 



considerable part of the food of some of the lizards that haunt the same situation. The 

 smaller Chironomids such as Tanytarsus and Cei-atopogon are found in the mountain 

 forests and the species may prove to be endemic. They have not been specially 

 collected and the number of species that exist is quite uncertain. Some are also found 

 on the coast, and about the salt marshes in the lowlands. 



More interesting than any of these is an aquatic black insect, which often frequents 

 strong mountain streams like that of the lao valley in Maui. Mr F. W. Terry, who 

 has studied its life-history, informs me that this species is of an undescribed genus, 

 allied to Tclmatogeiton. I observed it in great numbers in 1894 in the above-men- 

 tioned locality, when the river being in flood the flies were usually to be found sheltering 

 behind large rocks projecting from the stream. They are also found on other of the 

 islands, and are almost certainly endemic and an interesting addition to the scanty fauna 

 of the freshwater streams. As a rule this insect preserves badly in dry specimens, and 

 probably for this reason was not described in the systematic part of this work. In life, 

 when I first observed it, it appeared to me one of the most remarkable of the island 

 Diptera. 



PsYCHODiDAE. — Only two species of Psychoda have been recorded, though one or 

 two others have been observed. They are certainly all importations by man, and two of 

 the species have been bred from cow-dung and from wet soil. They are of no interest 

 in connection with the Hawaiian fauna. 



CuLiciDAE. — The two species of Stegotnyia, fasciata and saitellaris, are well-known 

 to all inhabitants as the 'day-mosquito,' owing to the fact that they are active at 

 irregular periods between daybreak and dark, whereas the ' night-mosquito ' or Culex is 

 active at dusk and throughout the night. All have been imported by man and there is 

 no native mosquito known, nor any true native name for a Culicid. 5". scutellaris is of 

 comparatively recent importation, as it did not come under my notice during the earlier 

 days of my collecting, though now very numerous and conspicuous. Both it and 5". fasciata 

 are very troublesome not only on the lowlands but also in parts of the lower forests, 

 where in the absence of pools or streams they can breed in great quantities in the small 

 collections of water that form in hollows of the limbs of trees or where these join the 

 trunk, as well as in the centres of decaying stumps. They do not generally seem to 

 range upwards above an elevation of about 1500 ft. The Culex is also a species 

 frequenting the coast and lower elevations, though exceptionally it has been found as 

 high as 4000 ft. above the sea. 5'. fasciata is, as is well-known, a species of notoriety 

 from its connection with yellow-fever, a disease at present unknown in the islands', and 

 we suspect that S. scutellaris has a similar connection with the fever called ' dengue ' 

 (which is sometimes epidemic), though others would attribute this to the Culex. For 



' A case of yellow fever has since been reported. 



