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V. On some Coleoptera /"ro/TZ the Iltncaiian Islands. 

 By D. Sharp. 



[Read March 5th, 1879.] 



This paper contains descriptions of thirty new species of 

 beetles fonnd by the Rev. T. Blackburn in the Sandwich 

 Islands. A like instalment, which I hope shortly to 

 offer to the Society, will complete the descrij^tions of the 

 discoveries made by ]\Ir. Blackburn up to the present 

 time in the islands. The species described are most of 

 them very minute insects, and this, unfortunately, will 

 create a great difficulty in ascertaining at present their 

 neai-est relatives, for it is an undoubted fact that our 

 knowledge of the Micro-Coleoptera is still quite rudimen- 

 tary, except in regard to European and North American 

 forms. 



I have felt compelled to establish four new generic 

 names, viz., Omicrus {Hydrophilidce), Monanus \Cucu- 

 Jid(E), Antilissus [Co/i/diidce) and Propalticus, this latter 

 being so peculiar a form that I am quite doubtful what 

 its affinities will ultimately prove to be, although I have 

 temporarily placed it with the Mycetopharjidm. 



Clytarlus microgaster is a most remarkable insect, by 

 reason of the excessive reduction in size of its hind body 

 or abdomen, which in the male sex is reduced to a small 

 appendage, reminding one of Avhat exists in some of the 

 parasitic Hymenoptera. I have not seen the female of 

 this interesting creature, and expect the hind body must 

 be at any rate somewhat larger than in the male. I almost 

 think 1 might cite this fact as a support of the suggestion 

 I made (Trans. Ent. Soc. Lond. 1878, p. 15), that the 

 paucity of individuals of most s})ecies of beetles in these 

 islands is possibly due to a diminution in the reproductive 

 powers of the species, owing to their long-continued isola- 

 tion, and the consequent absence of that amount of bi'eeding 

 between slightly-diffisreiit forms or races which is so 

 favourable to fertility of organisms. The minute size of 

 most of the species of these islands may perhaps also 



TRANS. ENT. SOC. 1879. — PART I. (aPR.) 



