422 STUDIES IN AUSTRALIAN XEUROPTERA, viii., 



basally with R in forewing. Cu with its strong anterior branch 

 (Cu,) carrying pectinate posterior branches only distally; the 

 weaker Cu 2 dichotomously branched. The three anal veins dis- 

 tinct, all branched. Cross-veins weakly formed, only moderately 

 numerous, scattered irregularly about on the disc. Main veins 

 and their branches hairy; cross-veins without hairs. Jugal lobe 

 and humeral process present, but no definite frenulum. 



A b d o m e n stout, cylindrical, shorter than the wings; formed 

 of eight complete segments, with reduced ninth and tenth also 

 present, the latter in the form of a small proctiger carrying the 

 aims. Eight pairs of spiracles, on segs. 1-8 respectively; the first 

 pair very large, the others small (Text-fig.5, asp,, asp.,). Anal 

 appendages of male consisting of a pair of large superior append- 

 ages of forcipate shape, and a single, broad, valve-like, inferior 

 appendage or hypandrium; between these lies the penis, with its 

 projecting penis-hooks or penunci. In the female, the abdomen 

 ends in a peculiar psammarotrum or sand-plough, from which 

 depend two tactile appendages; the anus lies dorsally above and 

 anterior to this organ, apparently upon seg. 8, but actually on 

 the reduced tenth segment. The genital opening lies in a slit at 

 the posterior end of the sand-plough, which is part of seg. 9. 



Eggs large, oval, soft, deposited in the sand, which adheres 

 to them, owing to a sticky secretion with which they are covered. 



Larva a soft, whitish, burrowing, blind, melolonthoid grub, 

 with small mandibles and maxilla? fashioned for sucking. 



Pupa a papa libera, not enclosed in a cocoon; lying free in 

 the sand. (See postscript, p.437). 



Distribution: Confined to Australia and Tasmania, so 

 far as known. Inhabitants of sandy places, including the central 

 desert region, as well as the coast-line. 



(A full account of the life history will be given in a later paper 

 of this Series). 



The Ithonidce. differ so much from all other Planipennia, that 

 I have no hesitation in proposing to separate them from the rest 

 as a naw Suborder Ithonoidea, distinguished by their remark- 

 able larva, the pupa free in the earth, without a cocoon, and the 



I 



