200 FAUNA HAWAIIEXSIS 



Mauna Blackburn. 



Mauna Blackb., Ent. JMo. Mag. xxi. p. 25. 



So far as I can find, the unique species of this genus is distinguished from some of 

 the Disenochus only by the slightly deeper ventral sutures, and by the peculiar form of 

 the thorax, which is small and subovate. The species might be placed in Disenochus 

 without making that genus much more heterogeneous than it is at present. 



( I ) Mauna frigida, Blackburn. 



Blackburnia frigida Blackburn, Ent. Mo. Mag. xv. p. 157. 

 Manna frigida id., op. cit. xxi. 1884, p. 25. 



Plate VI. fig. 9. 



There is a little variation in the large series of this species, but nothing remarkable. 

 A specimen searched for Laboulbeniaceae is labelled No. 1221 by Prof. Thaxter. 



Hab. Maui (Blackburn, Perkins): a single specimen only was found by Mr Black- 

 burn, at an elevation of about 10,000 ft. : Mr Perkins procured a good many specimens 

 about the crater of the great mountain, and also met with it at an elevation of 5 — 6000 ft., 

 February, May, October (Nos, 374, 602, 612, 655, Perkins). 



Disenochus Blackburn. 



DisenocJms Blackburn, Ent. Mo, Mag. xv. 1S78, p. 121 [nee Sharp, op. cit. xx. p. 218]. 



To the species for which this genus was originally established I now add several 

 others, making it by far the most comprehensive genus of this division of Hawaiian Ancho- 

 menids. It is noteworthy that, although the facies shows so much variety that some of 

 the forms look more like Pterostichini while others have the typical Anchomenoid appear- 

 ance, I can yet find nothing but slight structural distinctions between the forms that are 

 most different in appearance. 



The characters distinctive of the genus are as follows. Wings reduced to mere 

 vestiges about the length of the metanotum. Thorax margined ; one seta on each 

 side near the hind angle. Elytra with definite basal margin. Ventral sutures only 

 moderately deep. Sculpture not extraordinarily coarse, though in D. micantipennis it is 

 peculiar. Tarsi with the fourth joint not bilobed. The size does not exceed 10 mm. 



The first five species are all excessively rare, so that I have not seen sufticient 

 material to make me feel certain as to the forms being truly distinct species. 



Species such as D. fractus may be considered as central forms for this first division 

 of Hawaiian Anchomenids. I shall mention under Mysticomenus the fact that that 

 genus appears central for the whole tribe. Those who think that Hawaiian Anchomenids 



