BY R. J. TILLYARD. 



795 



cold. Out of thirty larvae brought from Wauchope, N.S.W., in 

 February, 1917, I succeeded in rearing only six to maturity. 



Before describing the spinning of the cocoon, we may profit- 

 ably study, somewhat more minutely, certain of the lai-val struc- 

 tures, as they are to be seen at the end of the third instar. 



The Mandibles (Te.Kt-fig.4, a, h) are a pair of huge curved jaws, 

 immensely strong, and of a 



rich dark brown colour. 

 They are smooth in outline, 

 and without visible teeth; 

 but an examination under a 

 higher power will show the 

 presence of about six small, 

 backwardly directed serra- 

 tions on the inner edge, close 

 up to the tip, as in Text- 

 fig. 4, 6. These undoubtedly 

 help in preventing the escape 

 of the prey, when once it has 

 been pierced by these power- 

 ful jaws. On the ventral 

 side of each mandible, there 

 is a very definite groove {gr) 

 which receives the maxilla, 

 lying directly below it. The 

 length of the mandible is 

 2-7 mm. 



The J/axiZ^fc (Text-fig. 4, cj 

 are not unlike the mandibles 

 in size and shape, but are 

 slenderer, and slightly more 

 curved towards the tip. They are entirely devoid of armature, 

 except for their very sharp points. Each maxilla carries a very 

 faint groove upon its dorsal surface, a little wider than the groove 



Text-fig. 4. 



* a, Mandible of larva of Pst/chopsis ekgam {Guer.), third instar; ( x 30). 

 b, Tip of same, to show the series of fine serrations; ( x 87). c, Maxilla of 

 same; c, cavdo; p, palpiger; st, stipes; ( x 30). 



