HYMENOPTERA OF THE HAWAIIAN ISLANDS. 201 



This species is allied to P.fuscipennis, Sm.., from which 

 it differs as follows : — The clypeus is yellow, the anterior 

 margin of the thorax is not testaceous, the tegulse are 

 paler, the punctuation throughout is finer and closer 

 (especially so on the metathorax, which is a little rugose 

 only in front and on the hind body). The basal joint of 

 the antennae is much more strongly compressed, being on 

 its flat face as wide as long, and has its front side more 

 strongly rounded than the hinder side. 



I have seen only a single male of this insect, which 

 occurred in September on Haleakala, Maui, at an elevation 

 of about 5000 feet. 



3. Prosopis Blackburni. 



Prosopis Blackburni, Smith, Proc. Linn. Soc. xiv. p. 68z ; Kirby, Ent. 

 Month. Mag. xvii. p. 85. 



The original description of this insect was founded, I 

 believe, on a single individual of each sex, the male being 

 an unusually brightly coloured one. At a subsequent 

 period I met with the species plentifully, and the exami- 

 nation of something like a hundred specimens has satisfied 

 me that it is subject to much variation. I think there- 

 fore that it will be well to supplement the description 

 with a further one, somewhat more in detail. The 

 distinctive characters seem to be as follows : — Head un- 

 usually elongate in both sexes, the width across and 

 including the eyes being scarcely equal to the total length. 

 The clypeus is abruptly truncate or even gently concave 

 at the apex. In the male the whole space below the 

 antennae is yellow, and this colour is produced in a trian- 

 gular form between the base of the antennse, and also 

 runs back as a gradually narrowing vitta adjacent to the 

 eyes on either side of the head. The extent of this colour- 

 ing is subject to occasional variety ; I have a specimen in 



