SOUTH AFRICAN BAGWORMS. 649 



fication, and is as yet not visible to the naked eye (text-fig. 

 2, A, b). The structure of the head-capsule now shows up as 

 consisting- of irregular plaques, giving the appearance of 

 alligator skin. These plaques are especially apparent on the 

 parietals, and are larger and more darkly pigmented on the 

 areas which make vip the pattern. On the front they are not 

 distinct, the surface here appears finely pitted. 



Antennae. — Second joint now considerably enlarged, four 

 times as long as the third and fourth joints combined (text- 

 fig. 2, E). 



Thorax. — The prothoracic shield is no longer uniformly 

 coloured, but the dark area is now interrupted by several 

 lighter spots, as shown in text-fig. 2, c. There is one mid-dorsal 

 oval spot in the median line, and a broader subdorsal, just 

 above the spiracle, broadening out cephalad to the front edge 

 of the shield. A similar subspiracular light spot starts below 

 the spiracle and extends dorso-cephalad until it meets the 

 subdorsal. On the front half of the neck-shield these thi-ee 

 light areas meet, and this entire part is thus light-coloured, 

 except for small dai'k patches around the bases of the setee. 

 The position of the sette corresponds to that during the pre- 

 vious instar. On the mesothoracic shield also we find the 

 first indications of a developing pattern in the shape of a 

 diffused narrow mid-dorsal and a broader sub-dorsal area of 

 lighter colour. The metathoracic shield shows a mere indica- 

 tion of a suffused light-coloured sub-dorsal patch. On the 

 intersegmental membrane between the second and third tho- 

 racic segments there has appeared a rudimentary spiracle. 

 A pair of ventral plates, fused in the middle line and bearing 

 two setfe, have appeared behind the coxas of the third 

 thoracic legs. 



Abdomen. — On the first and second abdominal segments a 

 rudimentary seta is found in front of the spiracle. Other- 

 Avise they agree in the arrangement of plates and sette with 

 the conditions found iu the second instar. Abd. 3 to 6 show 

 no differences from the second instar. Prolegs bear on the 

 average twenty hooklets. On Abd. 7 there is no change, 



