BY R. J. TILLYARD. 371 



it after emergence. In general appearance it resembles the 

 nymph of S. eustalacta, bub is riiuch slenderer and smaller. 

 Total length 17; abdomen 9-5; breadth of head 4; wing-cases 

 5 mm. Ze^'S fairly long. Abdo77ien with rows of curved hairs on 

 each segmental ridge. Labium: nientum rather short with 

 fairly broad base, median lobe triangular, but with no projecting 

 point; mental setce, 6 primary, 8 secondary. Lateral lobes rather 

 small, with six stiff lateral setce and a sharp terminal hook; distal 

 border carrying six well-formed and rather rounded teeth, very 

 similar in shape to tho.se of S. eustalacta, but not quite so higl'. 

 (Plate i.x., fig.5). Anal appendages of abdomen: superior 1*2 

 mm., with tip curved downwards; two inferior 1-4 mm., straight; 

 two lateral 1 mm., straight. 



Types: Coll. Tillyard (North Sydney). 



2. Choristhemis olivei Tillyard. (Plate v., fig.l3). 



Synthemis olivei, Tillyard, Proc. Linn. Soc. N. S. Wales, 1908, 

 p. 747. 



The following abridged description will serve to distinguish 



it : — 



(J. Total length 39, abdomen 30, hind wing 27 mm. 

 Wings: neuration fine, open; pterostignvi 1-7 mm., black. 

 Head: eyes grey-green in living insect; vertex black; front dull 

 whitish; clypens whitish with black sutures; labrnm white with 

 a fine transverse black line; labium pale brownish. Thorax : 

 prothorax brown, collar and two dorsal spots white. Meso- and 

 metathorax deep black; dorsal ridge creamy; two creamy ante- 

 humeral rays, straight and narrow, followed by two small white 

 spots; sides black with a large lateral irregidar mark like the 

 letter "n " flattened, and another patch low down, both creamy. 

 Abdomen very slender, cylindrical, black, marked withstiaw- 

 colour as follows — 2, a pair of dorsal marks; auricles creamy; 

 3-8, a pair of basal spots, and a pair of smaller central spots, 

 decreasing from 3 to 8; 9-10 black. Appendages: superior 

 1*8 mm., slender, straight, pointed, with two stiff hairs at tips, 



