1910.] FOSSORIAL WASPS OF AUSTRALIA. 283 



Hemithynnus wallisii Sm. 



Thynnus wallisii Sm. Cat. Hym. B. M. vii. p. 14 (1859), tf $ . 



Specimens of this species in the Berlin Museum have the antennae 

 of the male ferruginous. The locality given for these specimens 

 is New South Wales without a,ny more precise information. 



Oncorrhinus xanthospilus Shuck. (Plate XXXI. fig. 7, $ .) 



Oncorrhinus xanthospilus Shuck., Grey's Journal of two Ex- 

 peditions to N.W. and W. Australia, ii. p. 471 (1841), d . 



2 . Mandibles simple, not bidentate ; clypeus truncate at the 

 apex, finely punctured, without a carina. Head slightly convex, 

 nearly twice as broad as long, with a short, longitudinal, frontal 

 sulcus ; smooth, with deep sparse punctures above the base of the 

 antennae and on the vertex. Antennae shorter than the breadth 

 of the head ; the joints of the flagellum broader than long. 

 Posterior angles of the head rounded. Thorax sparsely punc- 

 tured ; the pronotum narrower than the head, twice as broad as 

 long, very slightly narrowed posteriorly ; scutellum much broader 

 than long. Median segment very short, obliquely truncate a 

 little behind the scutellum, the surface of the truncation finely 

 shagreen ed. Abdomen broader than the thorax ; very shallowly 

 and sparsely punctured ; the basal segment concavo-truncate 

 anteriorly, very narrowly depressed on the apical margin ; second 

 segment irregularly and finely transversely carinated, with a 

 strong transverse carina near the apex separated by a broad 

 groove from the strongly raised apical margin. Pygiclium not 

 contracted at the base, vertically truncate posteriorly, the surface 

 of the truncation broadly ovate and longitudinally striated, the 

 striae strong and arched at the base. Fifth ventral segment 

 coarsely longitudinally stria,ted. Intermediate tibiae moderately 

 thickened ; the first joint of the intermediate tarsi normal, not 

 thickened; tarsal ungues bidentate, small. 



Fusco-ferruginous, the legs and pygidium paler ; head black ; 

 the sides of the abdominal segments pale testaceous. 



Length 12 mm. 



Hob. South Perth, Guildford, W. A. (H. M. Giles). <$ $ in cop. 



" On Eucalyptus bloom. Fairly common." (Giles.) 



The disparity between the sexes is great and the female is not 

 so aberrant as the male, showing close relationship to other species 

 allied to the Macrothynnus group. The palpi are minute as in 

 Thynnus, the maxillary palpi two-jointed, the labial palpi three- 

 jointed. 



Maceothynnus simillimus Sm. 



Thynnus simillimus Sm. Cat. Hym. B. M, vii. p. 15 (1859), 3 . 



A male specimen sent by Mr. Giles differs from the typical 

 form from New South Wales in the somewhat less robust form, 

 the presence of a low longitudinal carina on the scutellum, and the 

 more triangular shape of the hypopygium. 



Hah. South Perth, W. A. 



