292 STUDIES IN AUSTRALIAN MEC01»TEKA, 1 , 



partially fused valves (fig.ll, v): the ninth segment ends dorsally 

 in a median bilobed appendage of small size, situated between 

 the base of the claspers. Jn female, seg. 8 carries a pair of 

 ventral gonapophyses (fig. 12, yp) with pointed, curved ends: 

 these form the ovipositor. Seg. 9 is normal; seg. 10 very short, 

 carrying the smail but distinct cerci {o. 



Genus N a n n o c h o r i s t a, n.g. 

 (Plates xvi.-xvii.) 

 Characters as in the family, to which may be added :— Hind- 

 wing slightly shorter and narrower than fore\ving: base of hind- 

 wing very distinctly narrowei'. Sc in forewing ending at or a 

 little before two-thirds of the wdng-length, either upon Rj (Plate 

 xvi., figs. 1, 3, 4) or upon C (fig. 2); in the former case, the ptero- 

 stigma remains open basally; in the latter, it is closed basallyby 

 the upcurved end of Sc and a small cross-vein descending from 

 it upon Rj. Between and Sc in forewing, two constant cross- 

 veins. Sc in hindwing very short, ending upon C either above 

 or before the level of the origin of Rs (this character is variable 

 for individuals of the same species). Pterostigma supported 

 below by a single constant cross-vein descending upon the dis- 

 coidal cell (dc). Second apical fork (Afo) always divided by a 

 single constant cross-vein, which therefore closes distally a single 

 post-discoidal cell (pdc) situated beyond and below dc close to 

 the apex of the wing. Below dc and ]'dc, a suh-discoidal cell {sdc) 

 is closed off by two constant cross-veins, the first descending 

 from R4+5 upon M^^o somewhat distad from t, the second de- 

 scending from Rg upon M^ at about the middle of the length of 

 pdc. Thyridinrti ov median fork {t) placed somewhat distad from 

 level of rJ] but before the beginning of dc. Median cell (inc) 

 completely closed, with Afo stalked, but Af4 sessile upon it. 

 Below and a little before the level of t, Cuj forks, sending out an 

 oblique upward branch Cuj^ which fuses with M3+4, thereby 

 completing the closure of the thyridial cell {tc). At the thyri- 

 dium, the pigmentation of the wing-veins is interrupted for a 

 short distance, so that there appears to be a short break in the 

 three veins meeting at this point; this formation I propose to 



