COLEOPTERA 403 



Fam. LUCANIDAE. 



Apterocvclus Waterhouse. 



Apterocyclus Waterhouse, Tr. ent. Soc. London, 1871, p. 315. 



This genus is not closely allied to any other. Mr Waterhouse alluded to its 

 superficial resemblance to the Chilian genus Sclcrostonnts. Apterocyclus is however 

 distinguished from Sclerostomns by the absence of a labrum and the nature of the 

 mandibles, and it is really nearer to the widely distributed genus Dorciis. I have no 

 doubt that the species are all wingless. 



The species of this genus are all confined to the island of Kauai. Very few 

 specimens are known of it, and it is most desirable that further information should be 

 obtained and published. At present I am obliged to distinguish seven forms as 

 species ; but it is possible that some of them may be merely varieties, and that A. foni- 

 iialis may be female of one of the other forms, all of which are known only in the 

 male sex. 



( I ) Apterocyclus watcrlioiisa', sp. nov. 



$ Brevis, latior, pedibus crassis, mandibula dente crassa, baud acuminata, sed fere 

 oblique truncata ; sutura elytrorum ad apicem angulatim prominula. Long. corp. 

 sine mandib. 20 mm., lat. i i mm. 



Plate XIII. fig. I. 



A single specimen of this remarkable insect is all that has been found. The 

 thorax is straight at the sides, with the hind angles much less rounded than in the 

 other species. The front tibiae are broad, strongly crenulate on their outer margin. 

 The middle and hind tibiae are remarkably thick, and have each a sharp denticle, 

 externally, below the middle. 



The thick legs, and the angular ape.x of the elytra, will render this form un- 

 mistakeable. I have named it in honour of Mr C. O. Waterhouse, who described this 

 interesting genus. 



Hab. Kauai (Perkins). 



(2) Apterocychts nninroi, sp. nov. 



t Niger, opacus, epistomate elongatim prominulo ; elytrorum margine laterali alte 

 elevato ; tibiis anterioribus apicem versus latioribus, externe crenulatis, medio dente 

 parum prominulo, angulo apicali bidentato. Long. corp. sine mandib. i6-|^ — 18 mm., 

 lat. 8^ mm. 



This species is very distinct by a number of structural characters. The mandibles 

 are slender, and in addition to the small tooth near the base, bear one or two very 

 minute tubercles, which are sometimes partly worn off, probably by attrition. The 



