196 THE CANADIAN ENTOMOLOGIST. 



Fourlh Instar. 

 Shape : No great variation is shown in this instar, save that the form 

 is perhai:)S a little more elongate in jjroportion to the preceding instars. 

 Head is more close to that of the adult, with a slight modification in the 

 eyes. The antennj«, which appeared three-jointed in the preceding 

 instar, show two processes arising from the main stem, which is still club- 

 shaped, somewhat curved outwardly, and three and one-half times as long 

 as wide. They are much lower down the edge of the eye than in the 

 previous stages. The wing-pads are much larger. The legs show a 

 greater development ; the fringing cili?e are more abundant in the second 

 and third tibiae, and the spines much larger and more regular. The 

 smaller claw of the anterior tarsus is further reduced, being now barely 

 one-third the length of the other. The combs on the third pair of tibite 

 are much more apparent, and there is a third broken row above the two 

 others. 



Size: Long, lo to 12 mm.; lat., 6.7 mm. 



The colour and markings are still unchanged. 



The three nymphs cast their skins for the fourth time in six, five and 

 seven days. Here the colour on leaving the cast skin is green, a very 

 light green, differing in this slightly from the other nymph. In a few 

 hours the normal spotted gray nymphal coloration is attained. The 

 integument even at this advanced period is so transparent that the con- 

 traction of the dorsal vessel is visible through the back. 



Fifth Instar. 



Shape : Differs from adult only in the more rounded abdomen and 

 absence of wings and strap-like appendages. The head is still propor- 

 tionally broader. The antennae are now much larger, much lower down 

 the inner margin of the eye, and very distinctly palmate, three and a half 

 times as long as wide. The wing-pads are large. The lower margins of 

 the eyes are provided with long fringing hairs. The legs are the same, 

 with one-jointed tarsi. The shorter claw of the anterior tarsus still 

 persists, very much reduced. 



Size: Long., 1 5 to 17 mm.; kit,, abdomen, 8.4 to 8.8 mm.; wing- 

 pads, 8,8 to 9.4 mm. 



Colour and markings a little more accentuated, but otherwise 

 unchanged. 



The three nymphs arrived at the adult instar, two in eleven and one 

 in eighteen days, but it is to be noted that the latter is an unduly long 



