353 Miss G. Ricardo — A Revision of 



species of Diodria, though it bears a general resemblance 

 to the genus and has a long third antennal joint ; but the 

 fore tibise are armed with a very distinct curved spine. It 

 cannot belong to the genus Cyrtophrys, Loew, the antenncs 

 having no apparent style. The abdomen is black, reddish at 

 the apex. 



Lapssinm. 



Table of Genera. 



1. Fore tibia3 with a carved spine at apex 2. 



Fore tibije with no curved spine at apex .... 3. 



2. Blue-black species marked with white abdo- 



minal spots. Moustache usually reaching 

 nearly to antennte, tubercle distinct on face . Thereutrla, Loew. 

 Small species. Moustache confined to oral 

 opening, no tubercle on face Metalaphria, g. n. 



3. Posterior transverse vein in a straight line, or 



almost so, with the vein closing discal cell . . 4. 

 Posterior transverse vein not so placed 6. 



4. Third joint of ante nnse notched at apex, usually 



with a spine Clariola, Kertesz. 



Third joint of antennsa not notched 5. 



6. Abdomen punctuate, third joint of antennae 



longer than thu first twojoints together .... Atomosia, Macquart. 

 Abdomen hardly punctuate, the third joint 



three times as long as the first two joints 



together Aphestta. 



6. First posterior cell closed or very narrow. . 



Abdomen bare [Nusa, Walker. :^ ixyvivij 



First posterior cell wide open or not very 

 narrow 7. 



7. Moustache confined to oral opening. Head 



orbicular, very much excised behind Maira, Schiner. 



Moustache not confined to oral opening. Head 

 semicircular, not usually so much excised 

 behind Laphria, Meigen. 



Thereuthia, Loew. 



Progr. Realschule Meseritz, 1851, p. 20 (1851), 

 Sccmdon, Walker, Ins. Saund., Dipt. i. p. 108 (1851). 



This genus was formed by Loew for a new species from 

 Australia, viz. Thereutria calcar, which Loew made the 

 type of the genus. He separated the genus from Laphria 

 by the presence of the curved spine on the fore tibiae. It is 

 as yet peculiar to the Australasian region. The species are 

 distinguished by the blue-black abdomen often marked with 

 white spots, by the blue-black legs, the tibise or femora 

 often yellow, the latter usually stout, curved, t\\Q face with a 

 prominent tubercle covered by the thick moustache, with 

 often long hair's continued to the base of the antenna, which 



