146 THE THTNNIDEOUS INSECTS OF AUSTRALIA. 
Thynnus, but having the head twice as broad as the thorax (which 
is tripartite), the sides of the mesothorax furnished “ processu 
alaaformi”); the maxillary palpi 6-jointed, with the joints subsequal, 
and the tarsal ungues simple. The type A. bicolor is 5 lines long. 
' The following is its specific character given by Dr, Erichson, 
together also with those of his four species of Thynnus:— 
Ariphron bicolor, —Rufus, capite piceo, abdotnine nigro apice rufo. Long. 5 lin. 
Thynnus Olivieri. —"iMas.; niger, pedibtis rufis, thorace supra fulvo villoso, abdomine 
supra 4—, infra bifariam flavo-maculato. 
Fem.— Rufa, capite subgloboso Iboraceaue immaculatis abdotnine piceo, segmentis 1—5. 
4-fariam flavo-maculatis, 1. lasvissimo. Long. TJ lin. 
Thynnus senilis, — Niger, albido«villosus pedibus concoloribus, clypeo flavo, (Mas.) 
Long. 5|—7Jlin. 
Thynnus fervxdns, —Niger, clypeo, mandibulis scutelloque flavis, thorace rufo-vario, 
abdotnine pedibusque rufis. (Mas.) Long. 6^ lin. 
Thynnus humilis, — Niger, cinereo-hirtellus mandibulis testaceis abdominis segmentis 
exolete flayo-marginatis, secundo transyersim bicarinato, (Fem.) Long. 3J lin. 
