48 FAUNA HAWAIIENSIS 



or abruptly, and still less so in the ? ; beneath, the costae obsolete or nearly so, the 

 sulcature shining, and the part of the segment beyond it strongly and abruptly raised 

 to a height greater than that of its basal portion, its depression narrow but deep in 

 front. 



Hab. Molokai mountains (3000 — 4000 ft.). Mountains of West Maui in the lao 

 Valley, and above Lahaina (3000 ft.). Lanai (2000 ft.). 



(35) Odynerus instabilis, sp. nov. 



Niger, mandibulis rufis, alis infuscatis caeruleo-iridescentibus. Caput densissime 

 punctatum. Mesonotum subfortiter punctatum, % postice irregulariter, interstitiis 

 crebre minutissime punctulatis. Propodei concavitas punctata. Abdominis segmentum 

 secundum basi subfortiter elevatum ; subtus, post sulcum fortiter elevatum, depressione 

 angusta sat distincta. 



Var. Tegulis rufis vel piceis. </?. Long. 7 — 9'5 mm. 



This species is very variable but quite distinct from any other. The surface in 

 some examples is quite dull, (especially in examples from Molokai), while in others 

 it is very shining. The mandibles are red, the head above the antennae densely, 

 but not very deeply punctured. The mesothorax is distinctly punctured, rather more 

 coarsely in the (/, and somewhat sparsely and irregularly on the posterior portion in 

 the ?. The propodeum is not rugose, but the posterior concavity is punctured. The 

 second segment of the abdomen is distinctly raised from the base ; beneath, it rises 

 up very strongly from the sulcature to an elevation much greater than its basal portion, 

 and there is a narrow but very distinct median depression. The wings are dark, 

 and have a blue iridescence. In examples from Maui the tegulae are generally red, 

 but in a few examples they are dark, as in the Lanai and Molokai specimens. 



Hab. Molokai, Lanai, and Maui, in the mountain forests (2000 — 5000 ft.). 



(36) Odynerus deinogaster, sp. nov. 



Niger, subnitidus, fronte, pronoto, et nonnunquam postscutello rubro-notatis, alis 

 infuscatis, caeruleo-iridescentibus. Caput, mesonotum, concavitasque propodei dense 

 fortiter punctata. Abdominis segmentum primum dense punctatum ; secundum supra 

 convexum, haud a basi elevatum ; subtus, sulco transverso nitidissimo, post sulcum 

 fortissime abrupte elevatum, costis et depressione obsoletis. c/ ? • Long. 7 — 8 mm. 

 (Plate L fig. 26 and 26 a.) 



Black, with a spot behind the antennae, the prothorax in front and sometimes the 

 postscutellum, red. Abdomen entirely black. Wings infuscate and with a blue iri- 

 descence. Clypeus hardly emarginate at the apex ; head above the antennae densely 



