I20 FAUNA HAWAIIENSIS 



variable in colour, being sometimes almost entirely pallid tlavous or fuscous (except 

 apically where they are most often dark) or entirely dark or alternately (on the same 

 nervure) annulate dark and pale. The tegulae, on the colour of which palaearctic 

 species are based, are also dark or pale or both. The frons and clypeus vary in the 

 same way. There are such numerous transitions in all these points, in forms otherwise 

 apparently identical, that it has been impossible to regard them as of any specitic value. 

 There is a distinct tendency in several species, particularly kanakamis and tarai, to 

 melanism in the Molokaian specimens. O. tainehanieha, oroiio, and hcvalicva appear 

 to me to be sharply characterized, well defined species. O. kanakamts is well separated 

 from the other species, but I am not sure that two distinct but closely allied forms are 

 not included ; farai drifts by certain transitions, not too complete however, to luorai, 

 which, in the absence of structural differences, I have reckoned merely as a var. of the 

 former. Opiina seems distinct by the short almost square vertex and the picturation 

 of the tegmina. 



The specimens from Molokai are often distinctly darker, particularly in O. kmiakanu.s 

 and O. tarai. The species may be provisionally divided as follows : 



1. Costa notably arched and thickened near the base; tegmina broad in 



proportion to tlieir length (j) hn'ahrc'a YJ\\\. 



\a. Costa not notably arched or thickened, tegmina usually somewhat elongate 2. 



2. Larger species, not less than 18 mm. in expanse of tegmina ; nervures robust 3. 



za. Smaller species, not more than 17 mm. in expanse; nervures slight 4. 



3. Pallid ; lateral margins of vertex subparallel ; disc of vertex black with a 



subcarinate median longitudinal pale stripe ; vertical fossette distinctly 



medianly longitudinally carinate (i) tamchameha Kirk. 



3(7. Dark ; lateral margins distinctly converging towards the apex ; no pallid 



median line on vertex and vertical fossette not carinate {2) kaiiakaiius Kirk. 



4. Vertical fossette distinctly bicarinate medianly ; tegmma yellowish hyaline, 



irregularly spotted {6) oroiio Kirk. 



4^?. Vertical fossette not carinate, or only somewhat obsoletely unicarinate 5. 



5. Base and apex of tegmina broadly dark smoky [or altogether so (var. i/wrai)\...(^) tarai Kirk. 

 5<z. Tegmina whitish or pale yellowish hyaline, banded or spotted with blackish- 

 brown 6. 



6. Vertex scarcely or not produced in front of the eyes, subparallel-sided, 



apically truncate (4) opuiia Kirk. 



6(7. Verte.x distinctly produced in front of the eyes ; tegmina immaculate ; vertex 



angulate apically (7) koanoa Kirk. 



Oliarus is almost cosmopolitan, both continental and insular. Scudder has doubt- 

 fully referred to it as an Insect from the Oligocene of N. America. 



(i) Oliarus taniehameha, sp. nov. 

 Plate IV. hg. 4. 



Pale sordid fuscous. Eyes, vertex on either side of the central narrow longitudinal 

 stripe (except the almost vertical lateral margins), tegminal nervures in part — black : rest 



