232 FAUNA HAWAIIENSIS 



a Metrontcnus could belong to any known species of a genus possessing setae even if 

 the difference as to setae were left out of consideration. 



With regard to the tarsal structure, I should explain that I have not made use 

 of it for dividing the genera because of the intermediate forms that exist. In the 

 preceding division of the Anchomenides I found that the species with lobed tarsi readily 

 separated from the others ; but here the reverse is the case. The character is, however, 

 of the greatest value for discriminating species, as there seems to be extremely little 

 variation in it. 



Division i. Lateral margin of elytra greatly curvate, rounded at the shoulders. 

 Species i^ — 24. 



(i) jMctromeints pahnae, Blackburn. 



Dyscohis pabnae Blackburn, Ent. Mo. Mag. xiv. p. 147. 



This species cannot be confounded with any other. It has a broad, lobed fourth 

 joint on the hind tarsus, and is dark in colour. M. rmdabilis has a large fourth tarsal 

 joint, but is red in colour and different in shape. Several species of Atelothrus approach 

 M. pahnae in shape and in the tarsal structure. 



Hab. Oahu. Not uncommon on the leaves of Freycinetia ; usually at an elevation 

 of about 1500 ft. (Blackburn). In several localities about Honolulu (Perkins). 



(2) Metrovicnus nmtabilis, Blackburn. 



Dyscolus imitabilis Blackburn, Ent. Mo. Mag. xiv. p. 148. 



Plate VI. fig. ij, a, b hind foot, above and below. 



This species is of rather depressed form, has the elytra moderately deeply striate, 

 and the fourth joint of the hind feet deeply divided so as to form distinct, slender, free 

 lobes. The colour is peculiar and quite characteristic. It is a rather bright yellow, 

 with the head somewhat infuscate and the elytra marked with black at the sides 

 behind. 



I have upwards of a hundred examples before me and all are recognisable at a glance 

 except in the case of six examples. Two are of an entirely yellow colour without the 

 black marks. Four, on the contrary, have the black colour very much extended, so as 

 to have the head quite black, the middle of the thorax infuscate, the elytra blackish with 

 the outer margin remaining yellow, and the suture and base yellowish. Though these 

 aberrant examples greatly resemble varieties of M. caliginosus and M. aeqiiaiis, yet the 

 structure of the tarsi is quite unmistakeable, and there is no doubt as to the distinctness 



