BY R. J. TILLYARD. 455 



slender, rather long, 1-2 and 7-10 enlarged. Colour: in the 

 young male, a beautiful reddish-pink ; in the mature male, 

 1-7 deep black, with a small basal olive-green mark on each 

 side, 2 also with a pair of apical spots, and 3-5 with a green 

 line alons sides for two-thirds from base ; underside brownish ; 

 8-9 brilliant red above, brownish-orange underneath ; 10, 

 black above, red on sides. Appendages: superior 0-5 

 mm., red, thick, slightly forcipate, upturned, very downy, 

 blunt; inferior 0-3 mm., thick, reddish, upturned, with a 

 rounded hairy inner lobe, and an apical point (viewed dor- 

 sally) ; in profile, sharply truncate, ending above and below 

 in a small black point (Plate xlix., figs. 3, 4). 



9. Very similar in build to cf, but differing from it as 

 follows: — Wiiifis hyaline; liead paler, eyes brown above, pale 

 yellowish-grey beneath ; postocular ridge between spots, red- 

 dish ; clypeus deep olive-green. Prothorax red, the middle of 

 the posterior lobe prolonged into a conspicuous semi-oval plate, 

 appearing, in profile, like a hook reaching back over the front 

 of the thorax. Thorax reddish, with a broad black dorsal 

 band, the red deepening to chocolate-brown in the very mature 

 female; legs pale brownish. Abdomen slightly stouter, 

 shorter and more cylindrical than in male, 7-9 slightly 

 swollen ; colour reddish-pink, with black lines in sutures, 

 gradually darkening with age to chocolate-brown ; in very 

 mature females, deep velvety-black, except 8-10, dark brown 

 Appendages 0-2 mm., divergent, pointed, reddish to brownish- 

 black, according to age. 



Hah. — Queensland, as far north as Cooktown, fairly com- 

 mon. — New South Wales, to as far south as Sydney. It is 

 found on small running creeks and rivers, from November to 

 March in New South Wales, but practically all the year round 

 in the tropics. 



Types: 9, unique, Coll. Selys; $<^, Coll. Tillyard. 



The mature male is very distinct, in colouration, from all 

 other A grionidce known to me ; the female is remarkable in 

 the form of its prothorax. 



