298 



STUDIES IN AUSTRALIAN NECROPTKRA, iv., 



frenulum consists of a single, strong bristle, usually blackish; 

 while, in the females, there are two, somewhat shorter and paler 

 biistles, one longer than the other. In D. insfabilis, it is pro- 

 bable that the same condition holds, but I have seen only three 

 females of this species. Thus it would seem that the form of the 

 frenulum is of no help in specific diagnosis, but that it enables 

 us to distinguish the sexes, when, as is usually the case, the 

 abdomen is too shrivelled for that purpose. The average expanse 

 of the females is about 1 mm. greater than that of the males, for 

 any given species. 



The following key will separate the five known species: — 

 ''Forewing with a conspicuous, nearly round, dark spot, en- 

 circled by a pale ring, situated near the posterior angle. 



Expanse l.^mm D. h'uwcida (Newman). 



Forewing with no such spot 1. 



ASmall species, expanse 15-16 mm., without any definite fenes- 



I tella, radial formula 3 + 1 -f 1 + 2 = 7, rarely 4+1 + 1+2 = 8. 2. 

 Larger species, expanse 16-22 mm., fenestella present; radial 



I formula totalling 8 or 9 3. 



'Tip of forewing barely falcate; deep mottled giey-brown 



colouration on forcwings D. hanlyi, n. sp. 



Tip of forewing distinctly falcate ; forcwings pale, with 

 irregular, 1 )rowi lish markings D. Jrogijntti, n. sj). 



/'Ground-colour of forewing uniform ochreous or medium 

 brown, without numerous irregidar markings, and with 

 little or no sign of numerous, oV)lique fascia- extending in- 

 wards from costa. Forewing slightly falcate, with moder- 

 ately rounded tip. Usually three luniUes. Radial formula 

 nearly always totalling 8. Hindwing \\'\(\\ 5-6 branches of 



Rs. Expanse 16-18 nnn D. humilis (Isiiiheach.). 



Forevvdng much more irregularly marked, Avith numerous, 

 distinct, oblique fascise extending inwards from costa; very 

 distinctly falcate, with pointed tip. Radial formula total- 

 ling 8 or 9. Hindwing with 6-7 branches of Rs. Expanse 

 1 9-22 mm D. inAabilis (McLach. ). 



3. Drepanacka humilis McLachlan. (Plate xiii., figs. 12-14). 

 McLachlan, Journ. Ent., Nov. 1863, pp.1 11-116. 

 The venation figured in Plate xiii., fig. 12, is that of a female, 

 expanse 1 8 mm. The following seem to be the most important 



3. 



