LARRID^. 139 



3. Crabro denticornis. 



Male. Length 3-4 lines. — Black; the head and thorax slightly 

 shining, the abdomen smooth and shining. The ocelli in a curve 

 on the vertex ; the fifth joint of the flagellum produced beneath 

 into a tooth or tubercle ; the clypeus with bright silvery pubes- 

 cence ; the mandibles bidentate at the apex, and having a large acute 

 tooth on their inner margin. The postscutellum yellow, scarcely 

 interrupted in the middle ; the scutellum slightly bituberculate ; 

 the metathorax with a central longitudinal channel, slightly im- 



' pressed at the base and deeply so towards the apex ; wings f usco- 

 hyaline, palest at their base. Abdomen smooth, shining, and im- 

 punctate ; occasionally the second segment has a small yellow spot 

 laterally. 



Hab. Sandy coasts of Maui. 



This may possibly be the male of C. mandibulars ; but the silvery 

 clypeus and dark wings obliged me to hesitate at uniting them, 



LARRIDiE. 



PISON. 



1. Pison iridipennis. 



Hale. Length 3 lines. — Black ; head and thorax finely and closely 

 punctured and slightly shining; abdomen shining and very de- 

 licately punctured. The face with silvery- white pubescence as 

 high as the emargination of the eyes ; the palpi rufo-testaceous. 

 The metathorax obliquely and finely striated, having a central lon- 

 gitudinal channel, and with silvery- white pubescence laterally ; 

 the wings hyaline and splendidly iridescent, the nervures black ; 

 the legs with silvery pile, which is very bright on the posterior 

 tibia? within. The abdomen has at the basal margin of the second 

 segment laterally a little silvery- white pubescence, on the apical 

 margins of the segments laterally a little silvery pile, only ob- 

 servable in certain lights. 



Hab. Honolulu. 



Rare ; a single female was taken by Mr. Blackburn, which differs 

 sexually, as in the following species. 



2. Pison hospes. 

 Female. Length 5\ lines. — Black, shining, with the head and thorax 



