800 



STUDIES IN AUSTRALIAN NEUROPTERA, Vll. 



velopecl, as miiiute processes flattened down close to tlie integu- 

 ment itself. In other places, they can be seen to be divided 

 into two short processes at an obtuse angle to one another. 

 From this form, the transition to a four-ra\'ed micraster is quite 

 a simple one. As microtrichia are developed from every single 

 unspecialised hypoderm-cell, in the regions in which they occur, 

 it follows that the same will be true of the micrasters in any 

 given region, as we find to be the case here. 



Piiiacida, or small plates of hardened brown chitin, carrying 

 one or more hairs or setie, occur upon the meso- and metathorax, 

 and also upon the sixth to eighth ab- 

 dominal segments. Each segment men- 

 tioned has a single pair of pinacula placed 

 more or less dorso-laterally. 



The simplest pinacula are those of the 

 abdomen, of which one is shown in Text- 

 fig. 8, together with its corresponding- 

 spiracle It is a somewhat irregular oval 

 patcli, which carries a single excessively 

 elongated and slender hair, quite unlike 

 any other hair to be seen in this larva, 

 and about one-third of a millimetre long. 

 The two pinacula of the eighth segment 

 are placed rather close together, on either 

 side of the mid-dorsal line. Those of the 

 J "p*^ seventh segment are placed further apart. 



Those of the sixth are much smaller, and 

 • Sp still further apart. Sometimes a vestige 



of a similar pinaculum may be observed 

 Text-fig 8.* upon the fifth segment also, in good 



chitin-preparations. 

 The pinacula of the meso- and metathorax are much larger 

 and darker areas, whose position has been already indicated in 



' Details from the integument of seventh abdominal segment of larva 

 of Ps. eJ e ff cms {Gwer.), third instar. d, A dolichaster; pn, pinaculum with 

 long, slender macrotrichion; s]!, spiracle, in situ; ( x 167). Three other 

 dolichasters surrounding the spiracle are omitted. 



