WHEELER— ANT LARV.E. 



309 



thoracic segment being greatly enlarged and projecting anteriorly. 

 Both preparations stained in toto and sections show that the portion 

 of the fat-body in this segment is sometimes heavily charged with 

 urate crystals, so that it undoubtedly functions as a storage kidney 

 till the Malpighian vessels are sufficiently developed to excrete. The 

 first and second pairs of prothoracic appendages of the ccthiops 

 larva are absent, but the third pair is very large and embraces the 

 sides of the head. The meso- and metathoracic segments each bear 

 a pair of slender pointed appendages, the first abdominal segment a 



Fig. 9. First larval stage (" trophidium ") of PacJiysima latifrons Emery. 

 A, ventral; B, lateral view. • 



huge leg-like pair, which are swollen and fusiform at the base and 

 run out into a long slender process which forms an obtuse angle 

 with the basal portion. The sternal region between these appen- 

 dages is protuberant and its cuticular covering, like that of the four 

 pairs of appendages is minutely prickly, unlike the smooth cuticle 

 of the remainder of the body. Sections show that both the appen- 

 dages and the sternal swelling are exudate organs, though the pro- 

 thoracic and abdominal pairs are much more important than the 

 others. The prothoracic appendages are filled with blood and very 



PROC. AMER. PHIL. SOC, VOL. LVII, V, AUGUST 8, I918. 



