70 



A REVISION OF THE THYNNIDjE OF AUSTRALIA. 



[Ht/menoptera.] 



Part II. 



By Rowland E, Turner, F.E.S. 



(Continued from these Proceedings, 1907, p. 290.) 



Subfamily THYNINN^ (continued). 

 Genus Thynnus Fab. 



Thynnus Fab., Syst. Ent. p.360, n.113, 1775. 



The species which I retain in this genus are very diverse in 

 appearance and structure, but I have thought it best in the 

 present state of our knowledge to use subgenera, rather than to 

 create an excessive number of genera, many of which might have 

 to be sunk when further material becomes available. I have 

 also been unable to examine the mouth-parts of several of the 

 species which might have thrown more light on the natural 

 arrangement. 



The structure being so varied, I shall only mention the char- 

 acters which serve to distinguish the genus from other Australian 

 genera of the family. 



(J. The hypopygium is always abnormal, but never in the form 

 of a long and strongly recurved acute spine as in Rhagig aster 

 and the allied genera. The head is never as strongly hollowed 

 beneath, or as strongly bearded on the sides as in Tachynomyia; 

 nor is the abdomen as strongly petiolate as in Ariphron. The 

 maxillary palpi of the last two genera are also strongly elongate, 

 which alone will distinguish them from all species of Thynnus 

 except the subgenus Zeleborla. 



<j>. The maxillary palpi are rudimentary, consisting of two, or 

 more rarely of three joints; and the second segment of the 

 abdomen is differentiated, more or less transversely carinated. 



