HYMENOPTERA 23 



flavescentibus. Tibiis anticis femoribusque haud fulvo-testaceis, mesonoto (?) postice 

 haud distincte punctato, abdominisque segmento 2 ventrali ruguloso, minus nitido 

 distinguendus. i%. Long. 7 — 12 mm. 



Very like the preceding in most respects, but the c/, so far as I know, never 

 has the abdomen spotted with white. 



Both sexes may easily be distinguished by their dark front femora and tibiae, 

 and the ? by the mesothorax being duller posteriorly, and without the distinct punctu- 

 ration of the preceding on that part. The second ventral segment also is evidently less 

 highly polished, its surface being evidently rugulose. 



Hab. Mountains of Hawaii (4000 ft.). Common generally. 



(12) Crabi'o {Solenius) iinicolor. 



Crabro unicolor, Smith, Cat. Hym. Ins. iv. p. 421. Blackburn and Cameron, 

 P. Manch. Soc. Vol. xxv. p. 169 (1885—86). 



Niger, alis infuscatis, et caeruleo-iridescentibus, mandibulis utriusque sexus cum 

 articulo basali antennarum nigris, clypeo argenteo-piloso. </ articulo antennarum sexto 

 haud fortiter dentato. cT?. Long. 7-5 — 13 mm. 



Black, the wings infuscate and with a steely-blue iridescence. Mandibles and 

 scape of the antennae black in both sexes, and the clypeus clothed with silvery 

 pubescence. Calcaria of the posterior tibiae bright testaceous in the $. 



Male with the sixth joint of the antennae very little produced at its apex beyond 

 the base of the following joint ; head in front with shallow, close and rugose puncturation. 

 Mesothorax with very shallow punctures, the surface somewhat smooth about the middle. 

 Propodeum longitudinally rugose in front. Abdomen with the second ventral segment 

 finely and not very closely punctured about the middle on its basal portion, towards 

 the hind margin densely and very minutely ; third segment somewhat depressed except 

 at the base ; the following segments deeply depressed. 



Female like the cf in most respects. The mesothorax posteriorly towards the 

 middle is smoother and more or less shining. Propodeum very finely longitudinally 

 rugose to the brow, at its anterior margin the rugosity is not so fine. Abdomen 

 with the second segment very finely but densely and quite distinctly punctured ; 

 beneath very highly polished on its middle portion and sparsely and clearly punctured, 

 very finely and densely on the lateral pubescent spots. Apical dorsal segment nearly 

 flat, its margins slightly raised, the surface somewhat rough, and punctured. 



Hab. Oahu, Molokai, Lanai and Maui; abundant on the coast and in the 

 mountains to an elevation of 4000 ft. or more. Preys on Tachinids &c. 



