HYMENOPTERA. 21 



ing in the centre ; the apical segment with oblong punctures ; 

 the ventral plate terminating in an acute spine. 



Hab. Australia (Swan River). 



39. THYNNUS FLAVIPENNIS. B.M. 



Male. Length 9 lines. Black : a line along the outer orbits 

 of the eyes which is continued along the margin of the vertex, 

 the mandibles, clypeus, a broad line up the inner orbits of the 

 eyes as high as the antennae, and the scape in front, reddish- 

 yellow. Thorax : the prothorax, a transverse spot on the meso- 

 thorax behind, a line over the tegulae terminating in a spot, 

 the scutellum, post-scutellum, and a reversed barb-shaped spot 

 on the metathorax, yellow ; there is also a yellow line at the 

 sides of the latter, and the tegulse are yellow ; the wings flavo- 

 hyaline, the nervures ferruginous ; the legs pale ferruginous, with 

 the anterior coxae yellow in front. Abdomen reddish-yellow, 

 each segment with a very large yellow spot on each side, the 

 hinder margin of each defined by a ferruginous stripe ; the apical 

 segment with a curved striation ; the ventral plate triangular, 

 with the apical angle obtuse. 



Hab. Australia. 



Resembles T. melleus : some examples of this species have a 

 large black or fuscous spot at the sides of the prothorax. 



40. THYNNUS FLAVOPICTUS. B.M. 



Male. Length 11 lines. Black: the mandibles, clypeus, 

 orbits of the eyes interrupted at their summit, the head behind, 

 and two oblique lines between the antennae, yellow. Thorax : 

 the anterior and posterior margins of the prothorax, two oblique 

 stripes on the disk of the mesothorax uniting at the base of the 

 scutellum, the tegulae and a line over them, a transverse spot on 

 the scutellum, two ovate spots on each side, the post-scutellum 

 uniting with a spot on each side, and the metathorax, yellow ; 

 the latter has a black angular spot in the middle of the base and 

 a larger one at the lateral basal angles ; the legs ferruginous, 

 with the coxae and femora yellow beneath ; wings hyaline, their 

 nervures fusco-ferruginous. Abdomen : each segment with a 

 broad interrupted yellow fascia in the middle ; the apical seg- 

 ment yellow, except at its base, and longitudinally striated ; the 

 ventral plate terminating in a sharp curved spine, which has a 

 smaller one on each side at its base ; beneath, the basal segment 

 with a trilobate spot, the four following segments with a very 



