452 FAUNA HAWAIIENSIS 



The structure of the prosternum Is much Hke that existing in Goniothorax conici- 

 collis ; in other respects the two insects are so different, that if the forms were placed 

 in Gonioryctus the two species in question would have to be widely separated in it. 



(i) Eunitidula sublaevis, sp. nov. 



Haud latus, minus depressus, tenuissime pubescens et parce punctatus, fere politus, 

 colore varians ; thorace minus transverso. Long. corp. 5^ mm., lat. 2, long, prothoracis 

 if, lat. prothoracis if, long, elytrorum 2 mm. 



Plate XIII. fig. 20. 



The colour is red varied with black, but the extent of the black varies greatly and 

 in one of the two individuals is more extensive than the red. The thorax is less 

 rounded at the sides than it is in Gonioryctits. The width is almost the same at the 

 front and the hind angles ; the hind angles are rectangular, and the front angles are less 

 rounded than in Gonioryctus ; the punctuation is distinct but fine, and comparatively 

 scanty so that the surface is shining. The elytra are only obsoletely striate-punctate 

 and there is very little punctuation of the abdomen. The male has the hind margin of 

 the pygidium rounded ; the female has it just perceptibly more pointed in the middle. 

 One pair. 



Hab. Maui, Haleakala, 5000 ft., iii. 1894 (no. 127, Perkins). 



Orthostolus, gen. nov. 



Sulci antennarii convergentes ; prosternum processu post coxas haud recurvato, 

 coxae posteriores distantes. Alae perfectae. 



This genus — for which O. robitstns is the type species — differs from Gonioryctus in 

 the prosternal process being scarcely at all curved upwards at the apex, by the smaller 

 eyes, with smaller facets, and by the smaller lobes of the tarsi. 



It is the most central form of the Hawaiian Nitidulidae, and like all the Hawaiian 

 allied forms it differs markedly from Br-achypeplus by the much more widely separated 

 hind coxae. Notopcplus is connected by means of Ortliostolits with the other Hawaiian 

 forms. 



(i) Orthostolus robustus, Sharp. 



Brachypeplus robtistus Sharp, Tr. ent. Soc. London, 1878, p. 134. 



Plate XIII. fig. 21, ^ under surface. 



I described this species from two specimens, 1^,1?. We have now a very large 

 series of nearly 300 specimens. There is a very considerable difference between the 

 sexes. The male is nearly always much darker in colour than the female, and slightly 

 narrower. It varies in length from 4^^ to 7 mm. and in breadth \\ — 2\ mm. The 



