COLEOPTERA 213 



The smaller extent of the dark pigment on the elytra readily distinguishes this from 

 the following species. 



Hab. Oahu (Perkins); Waianae mounts. 2000 ft., February 1S96. A small series. 



(2) Mysficoiiieiuis i/iys/iats, Blackb. 



Colpodes inysticus Blackburn, Ent. Mo. Mag. xiv. 1877, P- ^M- 

 JMetrovicmis >iiysticits Sharp, Tr. Dublin Soc. n. s. iii. pi. iv. fig. 2. 



Hab. Oahu (Blackburn): Waianae mountains, 2000ft., July. "Very local, but 

 not rare." I have seen only two specimens. 



Division 2. Hind tarsi more or less distinctly grooved (Plate VI. fig. 13). 



The grooving of the tarsi is in all the Hawaiian forms obscure, and in some of them 

 it requires a very rigorous examination for its detection. Nevertheless, it makes a fairly 

 satisfactory division of the Anchomenides. In many exotic forms the sculpture of the 

 tarsi becomes very perfect and remarkable. Possibly it may be a character that has 

 become diminished in the Hawaiian islands. In that case it is quite likely that 

 Mysticomenus and Apteromcsns of Division i are forms that formerly possessed the 

 grooves but have now lost them. Their general facies is that of members of Division 2, 

 and if they be excepted, this character — slight as it is in Hawaii — makes a perfectly 

 natural division of the Hawaiian Anchomenides. The character is easiest seen on 

 the outer aspect of the basal joint of the hind tarsus, and in some cases it can only 

 be detected there, and in the form of a slight longitudinal impression near the base 

 of the joint. 



The genera are easily tabulated as follows : 



Fully winged Colpocaccus. 



Unwinged, 



Mandibles somewhat elongate, Mecoiiieinis, Alcxosiomits. 



I no thoracic seta Metronunus. 



I thoracic seta, near hind angle Ateluthriis. 



Mandibles short ' , . . . ,,, ,, ., . 



i I thoracic seta, near middle Mesotnnsciis. 



\2 thoracic setae, i near hind angle, 1 near middle Flaiynus. 



Colpocaccus, gen. nov. 



Dysco/us, part, Blackburn, Ent. Mo. Mag. xiv. 1877, p. 143. 

 ColpodiscHS, part. Sharp, op. cit. xx. 1884, p. 217. 



Alae perfecte expHcatae, metasternum sat elongatum. Prothorax utrinque seta 

 unica, ad angulum posteriorem sita, munitus. Tarsi posteriores ad margines sulcati ; 

 articulo quarto parvo, emarginato, haud bilobato. 



