HYMENOPTERA 51 



somewhat strongly convex, especially in the <^ ; beneath very strongly and abruptly 

 raised behind the sulcature, the costae ill defined, subobsolete, the depression very 

 distinct, deep in front, the segment prominent on either side of it. 



Hab. Mountains of Oahu, both ranges. 



Obs. This species has a most remarkable resemblance superficially to O. oahuensis. 

 It is less robust and lacks the red spot on the sides of the second segment of the 

 abdomen. The second ventral segment is as different as it well can be, and there 

 are other important structural differences, so that I believe the two species are not 

 really at all closely related ; yet their general appearance is extremely similar, and 

 unlike other Hawaiian species. 



(41) Odynenis leiodemas, sp. nov. 



Praecedenti simillimus, eodem modo rubro-notatus, sed angustior. Mesonotum 

 minus dense punctatum, scutello sparsius ac subtilius. Abdominis segmentum secun- 

 dum subtus minus fortiter post costas elevatum. ? . Long. 7^ mm. 



This species is exactly like the preceding in its markings and the colour of the 

 wings, but is evidently narrower in form. The mesothorax is more finely and less 

 regularly punctured and more shining, the scutellum more finely and sparsely. The 

 second segment of the abdomen more strongly convex at the base longitudinally (when 

 seen from the side), while beneath it is evidently less strongly raised from the sulcature. 



Hab. Waianae mountains, Oahu. A single % taken. 



(42) Odynenis laevisiilcatns, sp. nov. 



Niger, nitidus, alis infuscatis caeruleo-iridescentibus, forma gracili. Clypeus vix 

 emarginatus. Capitis vertex subincrassatus ; frons densissime punctata. Mesonotum 

 nitidum, antice aequaliter, postice ad medium subsparsim, fortiter punctatum. Pro- 

 podeum laeve, concavitate sua dense punctata. Abdominis segmentum secundum 

 subelevatum vel fortiter convexum ; subtus, post sulcum transversum, ad altitudinem 

 partis suae basalis (vel magis alte) elevatum, depressione angusta distinctissima, sulco 

 ipso nitido, costis fere obsoletis. %. Long. 7 — 8 mm. 



Female black, wings infuscate, with blue iridescence. Apex of clypeus hardly 

 emarginate. Head above the antennae very closely punctured, the vertex incrassate. 

 Mesothorax strongly punctured, evenly in front, posteriorly, at least about the middle, 

 somewhat sparsely. The puncturation of the scutellum is also very distinct, but finer 

 than that of the mesothorax. Propodeum with the surface smooth and shining, 

 distinctly but not deeply punctured, densely so in the posterior concavity. Abdomen 



