1910.] F0SS0RIAL WASPS OF AUSTRALIA. 293 



a transverse band near the base of segments 3-5 obscure creamy 

 yellow. The colour is very variable. 



Length 8-9 mm. 



Hab. Mooraree, near Brisbane, Q. {R. Illidge). 



On Leptospermu'm blossom. 5 pairs in cop. 



Near L. optimus Sm. from Western Australia, and related, 

 though less nearly, to L. nubilipennis Sm. The female is related 

 to L. sulcatus Sm., but the depressions on the head are much 

 smaller and shallower than in that species. 



Lestricothynnus subtilis, sp. n. 



S . Clypeus strongly convex, broadly truncate at the apex, 

 very coarsely punctured, with a low carina from the base to the 

 apex. Head punctured-rugose, the interantennal prominence 

 very broadly truncate at the apex ; antennae inserted further from 

 each other than from the eyes, as long as the thorax and median 

 segment combined and of nearly even thickness throughout. 

 Thorax and median segment very finely and closely punctured, 

 most finely on the pronotum and median segment ; the pronotum 

 narrower than the head, the anterior margin very slightly raised, 

 the posterior margin almost smooth ; median segment rounded. 

 Abdomen elongate, rather slender, tapering a little at the ex- 

 tremities, the segments not constricted, very closely and finely 

 punctured, the sixth ventral segment without spines ; dorsal plate 

 of the seventh segment flattened, triangular, and longitudinally 

 striated. Hypopygium short, scarcely projecting beyond the 

 dorsal segment, broadly triangular, with a short apical spine. 

 Second abscissa of the radius longer than the third ; second 

 recurrent nervure received near the base of the third cubital 

 cell. 



Black, with short white pubescence on the sides of the thorax 

 and abdomen. Wings pale fusco-hyaline, nervures fuscous. 

 Length 19 mm. 



2 . Clypeus without a carina, smooth and shining. Head 

 closely microscopically punctured, twice as broad as long, rounded 

 at the posterior angles, with a delicate, longitudinal, frontal sulcus. 

 Pronotum rectangular, more than half as broad again as long, 

 narrower than the head, finely and sparsely punctured, with a few 

 setigerous punctures on the anterior margin ; scutellum trans- 

 verse, about three times as broad as long ; median segment 

 obliquely truncate from just behind the scutellum, very minutely 

 punctured. Abdomen sparsely and shallowly punctured ; the 

 second segment with a low transverse carina at the base and two 

 higher carinas, rather widely separated from each other, at the 

 apex, one being formed by the raised apical margin, the space 

 between them and the basal carina with about four low, ill-defined, 

 undulating and broken carinas. Fifth ventral segment coarsely 

 longitudinally striated. Pygidium vertically truncate posteriorly, 

 the face of the truncation rather narrowly ovate and coarsely 

 longitudinally striated ; the ventral plate extending ' a little 



