COLEOPTERA 231 



the shoulders of the elytra less prominent. Except for the longer trophi, this individual 

 appears scarcely to differ from some of the specimens of Mctroiuciiits latifrons. 



Hab. Maui. Lahaina (Koebele). 



(2) Mccoiiiciiiis putcalis, Blackburn. 



Anchoinenus pntcalis, Blackburn, Ent. Mo. Mag. xvii. 18S1, p. 227. 



The species will be readily recognised by the long mandibles and by the fact 

 that the lateral margin of the thorax is fine and less elevated than usual. The lateral 

 margin of the thorax is not so much incurved at the junction with the basal margin as 

 it is in the normal Mctroiiicni \ on the other hand, it is more incurved than it is in the 

 aberrant species of the latifrons group of jMctroiuoius. The elytra are yellow at the 

 tips but not at the sides. The antennae and legs are rather short, and the eyes are 

 reduced below the normal size. 



Hab. Maui. "In damp rotting leaves on the margins of a stagnant pool, at an 

 elevation of about 4000 ft. on Haleakala," April or May 18S0 (Blackburn). Haleakala, 

 in forest, 4000 — 5500 ft., March 1894, one specimen (Perkins, No. 384). 



Metromenus Sharp. 



Meti'onicniis Sharp, Ent. Mo. Mag. xx. 1884, p. 217. 



The characters of this eenus— amono; the Hawaiian Anchomenides — are tarsi 

 distinctly depressed longitudinally along each side, wings vestigial, thorax without 

 any seta. 



Most of the numerous species are confined to the island of Oahu, and several of 

 them are still very inadequately known. Their discrimination is a very difficult matter, 

 several of the species being extremely close to one another and so variable that know- 

 ledge of a good series is necessary to enable anyone to form an opinion as to their 

 validity. There are a few very distinct forms among them, such as M . palmac Blackb. and 

 M. perpolitiis. I ha\'e explained previously that in other genera, where thoracic setae 

 exist, the seta may, as an anomaly, be present on one side and absent on the other, and, 

 as an extremely exceptional case, may be absent from both sides : so that the individual 

 then becomes systematically a Metromenus. I believe this phenomenon really occurs 

 (and Mr Perkins shares this opinion), but that it is extremely rare. Under Atclothriis 

 stenopiis I have remarked on such a case. Still the evidence on this point is far 

 from being completely satisfactory. However interesting this question may be from 

 a biological point of view, it does not much affect the question of the systematic import- 

 ance of the seta. There are only one or two cases in which a species I have considered 



F. II. III. 30 



