HYMENOPTERA. 29 



or less interrupted, the fascia beneath produced laterally into a 

 hook-shaped form and slightly notched above; beneath, the 

 apical half of the basal segment yellow, with an oblique black 

 line on each side ; the second segment yellow, with a black stripe 

 on each side, and two or three of the following segments with a 

 yellow spot on each side. 



Hab. Australia (Sydney, Moreton Bay, &c.). 



73. THYNNUS CARINATUS. B.M. 



Male. Length 5^-6 lines. Black : the clypeus, anterior 

 margins of the face, inner margins of the eyes broadly, not ex- 

 tending to their summit, a line behind the eyes, two spots on the 

 hinder margin of the vertex, and a V-shaped mark between the 

 antennae, yellow ; the clypeus with a central longitudinal black 

 carina, not extending to the apex. The margins of the prothorax, 

 an oblique stripe and two spots beneath the wings, the tegulae, a 

 minute spot on the mesothorax, with a similar one on the scu- 

 tellum and another on each side of its base, the post-scutellum, 

 and an oblique stripe on each side of the metathorax, yellowish- 

 white ; wings hyaline, the nervures ferruginous ; legs ferru- 

 ginous, with the intermediate and posterior tibia? and tarsi 

 fuscous above ; the coxae black, spotted with yellow. Abdomen 

 shining; each segment, the two apical ones excepted, with a 

 curved white or yellowish-white line on each side, which termi- 

 nates at each end in a rounded spot ; beneath, the second, third, 

 and fourth segments with a similar curved line on each side, 

 but not having terminal spots. 



Hab. Australia (N.W. Coast). 



74. THYNNUS OPTIMUS. B.M. 



Male. Length 5^ lines. Head, thorax, and abdomen black 

 above and ferruginous beneath ; the mandibles, clypeus, orbits 

 of the eyes, and a bell-shaped spot above the antennae, yellow. 

 Thorax : the margins of the prothorax (the anterior one inter- 

 rupted), an oblong spot on the disk of the mesothorax, the tegulae 

 and a line over each, a spot on the scutellum, the post-scutellum, 

 a longitudinal line on the metathorax, its sides, a spot on the 

 coxae, a transverse one on the breast, and several large ones be- 

 neath the wings, yellow ; wings hyaline, the nervures ferruginous. 

 Abdomen : a large yellow spot on each side of the segments, 

 a line between the spots ferruginous ; beneath, a yellow spot on 

 each side of the second, third, and fourth segments. 



Hab. Australia (Swan River). 



