BY R. J. TILLYARD. 37^ 



fore-, middle-, cand hind-legs are — fore, 5,5-5, 2-5 nun.; middle, 6, 

 6, 2-5 mm.; hind, 8, G, 3"5 mm. Wing-cases narrow, about 7'5 

 mm. long, reaching to just beyond segment 3 of abdomen. 

 Abdomen very short, 12 mm., first three segments wider and 

 longer than the rest; rounded above, flat beneath; segments 5-9 

 of about equal length and width, segment 10 shorter but of same 

 width. Caudal gills (shrivelhd) 10 mm., blackish, the lateral 

 ones showing thick triquetral bases. 



[See Plate xxxiii., fig.l. N.B. — The caudal gills, as sketched 

 in the Plate and enclosed in a dotted square, are reconstructed 

 from the sketch made of the gills of the four-months old larva, 

 and must not be taken as absolutely accurate.] 



The colour of the larva is apparently a uniform dull dark 

 brown all over. 



Date of emergence. — The eggs aje laid in November, and there 

 i.=i no doubt, judging from the progress of the larva in captivity^ 

 that they are full-fed in a year. The perfect insect, in the 

 Sydney district, begins to emerge during the last week of Sep- 

 tember, and continues coming out till the end of October. In 

 the colder districts of Kosciu.sko and Victoria^ newly emerged 

 individuals may be found late in January, by which time the 

 insect has completely disappeared again in the Sydney district. 



Hah. — Fast mountain-streams in New South Wales and 

 Victoria. 



The perfect insect has been described by de Selys, and again 

 by Rene Martin^ from specimens taken by Capt. Billinghurst at 

 Alexandra, Vic. In my paper on "New Australian Species of 

 the Family Calopterygidce''-\ I have compared it with D. 

 euphceoides and have corrected some errors of description due to 

 the fading and changing of the brilliant colours in dried speci- 

 mens. I have never, in the Sydney or Kosciusko districts, 

 noticed the large range of variation in size and colour noticed by 

 Martin. 



* " Les OJonates du Continent Australien," Mem. Soc. Zoob de France, 

 1901, p.243. 



t These Proceedings, 1907, p.39S. 



