BY R. J. TILLYARD. 491 



S. guttata. S. nigra. 



Frontal spots of male 1 mm. Frontal spots of male close- 

 apart, together. 



No white spots at bases of Four distinct white spots at 



wings in male. bases of wings in male. 



Abroad straw-coloured trans- No band at all across the 



verse band across the mesonotum. mesonotum. 



Abdomen much spotted with Abdomen almost entirely 



yellow. black. 



Besides these differences, S. guttata is a smaller insect (especially 

 the 2); though on the other hand the pterostigma in guttata is 

 slightly larger than in nigra (especially in £). 



In some ways S. nigra shows closer affinity with S. brevistyla 

 than with S. guttata, notably in having the four spots at the bases 

 of the wings, and in lacking the transverse mesonotal band. 



The four closely allied species, viz., virgula, brevistyla, guttata 

 and nigra, may now be easily distinguished by the following 

 key : — 

 A. Superior appendages of $ short. 



-n f A pair of dorsal humeral yellow stripes on thorax virgula. 



I No dorsal humeral stripes on thorax G. 



p f Four distinct spots at the bases of the wings in $ D. 



iNo spots at the bases of the wings in £ guttata. 



„ J Abdomen much spotted, a large yellow spot on 7 brevistyla. 



I Abdomen almost entirely black , nigra. 



II.Macromia Tillyardi Martin. 



Three females of this magnificent insect were taken by me at 

 Kuranda, N.Q., in January, 1905. As M. Rene Martin is about 

 to issue his work on the Corduliinse, it seems fitting that the 

 record and description of so fine a species should appear in his 

 new work. I have therefore sent him my description of the insect 

 together with the type-specimen. It will be sufficient in this 

 paper to give a short description only, so that the insect may be 

 recognised by Australian collectors : — 



This is by far the largest of the Australian Corduliinse. 



(J. Unknown. 



