BY K. J. TILLYARD. 471 



►Suutliern form, in spite of its Queensland label. These are (d) 

 the colour of the prothorax, metallic green witli the margins and 

 the rounded posterior lobe yellow, (b) the colour of the j)ter(j- 

 stigma, yellowish, surrounded by thick black veins, and (r,) the 

 yellow colour of the "deuxieme article" of the antenn;c (the 

 actual joint that is yellow is the scape, but de .Selys' measure- 

 ments show that he mistocjk the scape for the second joint, oi' 

 pedicel, <jwing to the swollen base of insertion appearing like a 

 true joint). All these three charactei's are distincti\e of the 

 common Southern form. On the other hand, all the specimens 

 that I have seen from Queensland have the prothorax almost 

 entirely yellow, the pterostigma black, and the scape of the 

 antenna? also black. 



The two males described by de Selys in 1886 clearly belong to 

 the common Southern form, as both the measurements and the 

 description of the appendages testify. 



Thus we have to conclude that possibility (2) above is the 

 correct solution of this difficult problem. The key to the species 

 here giN'en, and the naming of the new species described here, are 

 both based on that supposition being correct. 



Key to the Species of the Genus Synltdts. 



I' 6 witla superior appendages strongly forcipate, blackish; 

 9 with seg. 10 and appendages dark (either metallic 

 I green or black) 1. 



6 with superior appendages elongated, creani}'- white; 9 

 ^ with seg. 10 and appendages creamy-white. S'. alhioindaT'xWyAxA. 



■ Very slender forms (hindwing about 27 nun.), with verj^ 



narrow wings and short black pterostigma '1. 



1. - Larger species (hindwing aVjout 32 mm.), not so slender, 

 \vith more densely-veined wings and longer yellowish 

 or brownish pterostigma 3. 



'Superior appendages of i with a prominent inner tootli at 

 about one-fourth of the length from the apex; abdo- 

 men O'b mm. wide in middle; greatest width of fore- 



2. - wing 4 '5 mm «S'. stlyi<i, n. sp. 



Superior appendages of 6 without a prominent inner tooth 



towards apex; abdomen only 0*4 mm. wide in middle; 



greatest width of forewing only 4 mm S. tropicus, n.sp. 



