HYMENOPTERA. 15 



male, but much darker ; the line takes a semicircular curve in 

 the centre, then a downward, and again an upward curve to the 

 lateral margin; the second segment transversely striated, the 

 apical one longitudinally so. 



Hab. Australia (Sydney). 



11. THYNNUS INSIGNIS. B.M. 



Male. Length 15 lines. Head and thorax black ; abdomen 

 reddish yellow ; the legs ferruginous ; the antenna black, the 

 scape ferruginous at the base and apex ; the clypeus, labrum, 

 mandibles, and orbits of the eyes yellow ; the yellow line inter- 

 rupted at the top of the eyes ; the tip of the mandibles black. 

 The thorax densely clothed with short silky white pubescence, 

 that on the metathorax longest; the posterior margin of the 

 prothorax and the tegulae yellow ; the wings slightly coloured. 

 Abdomen truncate at the base, and gradually tapering from 

 thence to the apex ; the extreme base black ; each segment with 

 a round ferruginous spot on each side, united by an arched 

 line of the same colour, which curves forwards to the basal 

 margin of each segment ; the apical margins of the segments 

 semitransparent, and having a beautiful radiating series of dark 

 hair-like lines springing from the basal margin of each segment ; 

 the apical segment with a semicircular space at its base striated 

 longitudinally, beyond this the striation is transverse. 



Hab. West Australia (Perth). 



12. THYNNUS SIMILLIMUS. B.M. 



Male. Length 15 lines. This species is coloured like T. 

 Wallisii, with the following differences : the tegula3, prothorax, 

 and legs entirely black, but pubescent as in T. Wallisii; the 

 clypeus widely ernargiate, the abdomen subtruncate at the base ; 

 the segments have a similar transverse upwards and downwards 

 curved ferruginous line, but the segments are pale beneath the 

 line ; the apical segment has a semicircular margined space at 

 its base, which is longitudinally striated ; the segment has a 

 curved striation beyond ; the margin of the lower ventral plate 

 is curved and entire. 



Hab. Australia (Sydney). 



13. THYNNUS VESTITUS. B.M. 

 Male. Length 1\ lines. Black : the head and thorax densely 



clothed with a white downy pubescence. The mandibles, cly- 

 peus, a line on the inner orbits of the eyes as high as the inser- 

 tion of the antennae, a narrow line behind them, and two oblique 



