1910.] FOSSORIAL WASPS OF AUSTRALIA. 281 



Gymnothynnus (?) trianguliceps, sp. ii. (Plate XXXI. 

 fig. 4, 2 ■) 



2 . Mandibles falcate, rather long and acute at the apex. 

 Clypeus slightly produced, truncate at the apex, without a carina. 

 Head very thin, slightly convex, as long as the breadth on the 

 anterior margin, much narrowed posteriorly, subtriangular, nar- 

 rowly ti'uncate posteriorly, subopaque, with a few scattered 

 punctures, an obscure longitudinal carina on the front, the lateral 

 margins slightly raised. Pronotum rectangular, a little longer 

 than broad, flat, subopaque, and without punctures, the lateral 

 margins slightly raised, broader than the posterior margin of the 

 head. Scutellum shining, very small ; pleurae finely aciculate. 

 Median segment scarcely longer' than the scutellum, broadened 

 from the base and obliquely truncate posteriorly. Abdomen 

 much broader than the thorax, the segments divided into two 

 nearly equal parts transversely, the basal portion raised and 

 broadly emarginate in the middle posteriorly, the apical portion 

 strongly depressed, the sculpture of the second segment not 

 differentiated. Pygidium long, elongate-ovate, convex, sub- 

 carinate longitudinally, not truncate or deflexed, with long grey 

 hairs at the base. 



Fuscous ; the legs and mandibles fusco-ferruginous ; pygidium 

 testaceous ; the depressed apical portions of the abdominal 

 segments pale shining luteous. 



Length 4 mm. 



Hah. Cossack, W. A. (J. J. Walker). 



Allied to lesceuji described above, but the shape of the head is 

 very different. 



HEMITHYNNUS PRiESTABILIS, Sp. n. 



c? . Clypeus transversely rugulose, almost smooth at the apex, 

 deeply triangularly emarginate, the angles of the emargiiiation 

 produced into short spines, a narrow and shallowly impressed 

 line from the base not reaching the apex. Head finely and 

 closely punctured, thickly clothed with long fulvous pubescence, 

 which is longest between the antennae and on the cheeks, with a 

 shallow frontal sulcus which reaches the anterior ocellus. Antennaa 

 a little shorter than the thorax and median segment combined, 

 the apical joints tapering and slightly arcuate. Thorax finely 

 and closely punctured, the anterior margin of the pronotum 

 rather strongly raised, the angles not prominent ; the pronotum 

 and scutellum clothed with sparse and long fulvous hairs. Median 

 segment more finely and shallowly punctured, the pubescence on 

 the sides long and white. Abdomen slightly fusiform, shining, 

 finely and very sparsely punctured ; the apical dorsal segment 

 narrowly truncate at the apex, with curved striae ; a thick tuft of 

 long fulvous hairs below the dorsal segment and above the hypo- 

 pygium, which is produced on each side near the base into a sharp 

 angle, thence triangular, with the sides curved upwards to the 

 base of the slightly recurved apical spine. Second abscissa of the 



