1 8 FAUNA HAWAIIENSIS 



Both sexes entirely black, the wings infuscate, and in the d" with a distinct blue 

 iridescence; clypeus with silvery pubescence. 



Male with a prominent tooth at the apex of the fifth joint of the flagellum of 

 the antennae, as in the preceding species. 



Head and thorax entirely dull with very shallow subobsolete puncturation, hardly 

 visible in some examples. Female with the thoracic puncturation, and especially that 

 of the scutellum, much more distinct than that of the ^ , the mesothorax posteriorly and 

 the scutellum more or less shining, but variable in this respect. Second ventral segment 

 of the abdomen with the surface exceedingly finely rugulose, not highly polished, in the 

 (/ with very fine indefinite punctures about the middle, in the ? with remote but 

 larger ones. 



Hab. Hawaii, various localities ; common at an elevation of about 4000 feet. 



Obs. This species is variable in size and sculpture ; the % is at once distinguished 

 from C. molokaiensis by the black scape and mandibles, the <^ is very similar but the 

 scutellum and the mesothorax posteriorly appear to be always quite dull. 



(6) Crabro (Solenhts) tumidoventris, sp. nov. 



Praecedenti simillimus, sed abdominis segmento secundo ventrali fortiter convexo, 

 mandibulis ? ex majore parte pallidis distinguendus. <} antennarum articulo sexto 

 fortiter dentato. d"?. Long. 7 — 9"5 mm. (Plate I. fig. 7.) 



Very like the preceding in general appearance ; </ with the scape and mandibles 

 black ; % with the scape of the antennae black, the mandibles white ; </ rarely with 

 some indication of a pale spot on the mandibles. 



Fifth joint of the flagellum of the antennae produced into a prominent tooth at 

 the apex in the </■, the front of the head and the mesothorax with very shallow 

 rugose puncturation ; propodeum more or less longitudinally rugose in front, and in 

 this sex usually with a few fine transverse raised lines above the insertion of the 

 abdomen. Second ventral segment of the abdomen very convex longitudinally and 

 transversely, the surface shining, finely and rather remotely punctured about the 

 middle, more closely towards the sides, and very densely and minutely on the circular 

 pubescent spots ; fourth and fifth segments generally strongly depressed, sometimes 

 the fourth less strongly, and the fifth and sixth more so. Basal joint of the front 

 tarsi unusually wide, about twice as long as its greatest width. 



Female very like the cT, except for the white mandibles and sexual differences. 

 Mesothorax and scutellum quite dull ; second ventral segment shaped as in the d", 

 finely and distincdy punctured in the middle, densely and very finely on the pubescent 

 spots. Apical dorsal segment very narrow between the lateral carinae, more or less 



