HEAD, MOUTH-PARTS, ORTHOPTERA EUPLEXOPTERA 277 



into the lateral wall of the postpharynx. The caudal end is 

 on the dorsolateral margin of the postpharynx and supports its 

 dorsal and lateral walls. The paralingua is an inverted Y-shaped 

 sclerite on the lateral aspect cephalad of and fused with each 

 pharyngea. To the strongly chitinized dorsal stem of the Y a 

 prominent linguatendon is attached. It extends laterad, and, 

 after passing over the rectotendon of the mandible, enters this 

 structure. The caudal portion of the subgusta is broad and the 

 cephalic is constricted between the two paralinguae. The lin- 

 gula is the distinct setiferous sclerite fused by a narrow neck 

 to the cephalic end of each paralingua. The dorsal surface of 

 the parapharynx is constricted between the two lingulae. The 

 salivia is a large chitinized area occupying the ventral half of 

 each lateral aspect of the hypopharynx. Its caudal angle is 

 produced into an arm which supports the salivos on the ventro- 

 meson. A slightly chitinized area lies cephalad of each lingula 

 and dorsad of each salivia. The ventral aspect of the hypo- 

 pharynx is concave and furrowed on the meson and the chitinized 

 extensions of the saliviae occupy the caudolateral portions. The 

 salivos is protected on the ventral side by a thick triangular 

 membrane. The salivary duct is very small and extends caudad 

 for some distance before bifurcating. The oscula is narrow and 

 indefinite and the salivos is located dorsad of the cephalic part 

 of the mentum. 



• The parapharynx in Diapheromera (fig. 163) is compressed and 

 boot-shaped. The pharyngea is a large irregular sclerite extend- 

 ing into the lateral and ventral walls of the postpharynx. Its 

 cephalic end terminates indefinitely in the membrane laterad of 

 the subgusta. The subgusta is deeply furrowed on the meson, 

 and each caudolateral half is strongly chitinized and fused to the 

 pharyngea without indication of a suture. The paralingua is the 

 ax-shaped sclerite on each lateral aspect of the subgusta. Its 

 dorsocaudal angle is pointed, the caudoventral bifurcated, and 

 the linguatendon is attached to its laterodorsal arm. The 

 cephalodorsal angle is more chitinized than the other parts and 

 curves cephalomesad, while the opposite angle extends cephalo- 

 ventrad and meets the dorsal extension from the caudal part 



