COLEOPTERA 585 



Distinct by its small (but variable) size and otherwise from all but the following. 



Hab. Oahu, Molokai. — Molokai, 3000 ft. ; since found on Oahu near the coast. 

 Not common. 



(12) Holcobins fratcr, sp. no v. 



Minor, parum robustus, subtiliter pubescens, fusco-niger (nonnunquam plus minus 

 brunneus aut rufescens) antennis rufo-testaceis, et sat brevibus. Pronotum totum 

 opacum et subtiliter granulatum, lateribus desuper aspectis baud quasi-emarginatis. 

 Elytra subtiliter striata, striis impunctatis, interstitiis obsolete rugulosis. Long, circa 

 4 mm. 



The type of this species is from Kauai, but it also occurs on Oahu. Examples 

 from the latter island, that I have recently taken, generally have the pronotum less dull 

 and granulate than the type and are brighter in colour. 



Hab. Oahu, Kauai. — ^Kauai, 2000 ft.; Oahu, 1200 — 1500 ft. 



XvLETOBiu.s Sharp. 



Xyletobius Sharp, Tr. Ent. Soc. London, 1S81, p. 519. 



The species of Xyletobius form a number of groups, difficult to define, but readily 

 recognized after a reasonable time spent in the study of a representative collection. 

 Some of these groups will certainly form distinct genera, when they are still further 

 studied. In these descriptions I have not used characters drawn from the underside 

 of the insect, especially the distance between the middle co.xae, which is much greater 

 in some (e.g. X. inonas) than others, because it appears to vary in the se.xes of some 

 species. Nevertheless, it will certainly prove an important character. My grouping 

 is largely based on male characters (i.e. the length of the antennae) which is of course 

 unsatisfactory, but, at present, the best method I can discover. 



I. Species in which the posterior lateral angles of the pronotum are distinct and not so rounded off as 

 to be effaced. Pronotum always very uneven, raised or tuberculate, so that in lateral aspect the upper 

 outline is angulated towards the middle A', tcahuighamii, durranti, syhiestrii, /lawaiiensis. 



II. Species with the posterior pronotal angles rounded off and effaced ; pronotum very rarely formed 

 as in the preceding section All the other species of the genus. 



The latter group may be subdivided into a number of sections with the following 

 characters : 



(i) Species entirely black, with the antennae very strongly serrate (for the genus), these and the legs 

 black, the elytral striae hardly at all punctured (elytra scantily tomentose and pronotum very little 

 convex above in profile in A', /nidus) V. iiiidus and } nigri/iiis Sh. 



