310 



The Large Poplar Longhom 



while that of the metanotum shows a double row of similar bristles with 

 a depression between them. 



The dorsal areas of the first seven abdominal segments resemble each 

 other in appearance; they have fleshy protuberances which show two 

 transverse depressions and bear short, stiff bristles. These bristles are 

 arranged as in Fig. 10 a, and the areas which bear them are known as 

 the ambulatory ampullae (aa). 



(a) (b) 



Fig. 10 a. Larva of S. earcharias, dorsal view (greatly magnified), aa = ambulator}' 



ampulla; is = intersegmental skin; p=pronotum; 2>a = parascutal area; pl = pleural 



lobe; ps^postscutellum. 

 Fig. 10 6. Larva of S. earcharias, ventral view (greatly magnified). es = eusternum; 



%p = hypopleurum; Z = labrum; m = metanotum; mn = mandible; mx = maxillae; 



o — ocellus; j) = pronotum; pl = pleural lobe; pr = presternum; <s/Z = sternellum. 



Surrounding each ampulla is an elliptical area, slightly swollen 

 laterally, called the parascutal lobe {pa). Behind the ampulla on each 

 segment is the postscutellum (ps). The eighth segment resembles the 

 previous segment but has no ampulla and therefore no parascutal area. 

 The ninth is similar to the eighth only it shows no postscutellar area. The 



