NO. lO 



MORPHOLOGY OF GNATHOTRICHUS SCHEDL 



71 



literature available, only two species have been found to be studied 

 at the present. These are Dcudroctonus z'alcus Lee., investigated by 

 Hopkins, and Chacfopfcliiis z'cstitiis Fuchs studied by Russo. The 



Cl-x Eph/ -Lar 



Hst 



Fig. 37. — GnathotricJius maleriarius Fitch : Head of fully-grown larva ; A, fron- 

 tal aspect, B, ventral aspect, C, lateral aspect, D, occipital aspect. 



Ah, antenn.i; CI, clypeus, seta clypei; Eg, entogular plate; Ep, epicranium; Eph, epi- 

 pharynx; Est, epistoma; Fr, front; Ge, gena; Gu, gula; Hst, hypostoma; Lar, labrum, 

 setae labralis; Li, ligula; Md, mandible; Mc, mentum; Mx, maxilla; Occ, occiput; OcA, 

 occipital apodeme; Pr, pregena; Pst, pleurostoma; SM, subraentum; Ve, vertex; a, sutura 

 metopica; b, sutura fronto verticale; c, seta geno mediana; d, seta fronto lateralis; e, seta 

 epistomalis; /, seta verto mediana; g, seta verto lateralis; h, seta geno lateralis; /, seta 

 epicrano-lateralis; j, gular suture; k, maxillare foramen; stL, sternal lobe. 



comparison of the setal arrangement with the latter species will be 

 given at the end of each chapter. 



Clypeus. — As mentioned before, the clypeus (fig. 37, CI) is well 

 developed in the larvae. It consists of a nearly rectangular plate 

 which is heavily chitinized, distinctly emarginate anteriorly and 

 broadly rounded antero-laterally. Basally it is separated from the 



