﻿TEÄGARDH, CONTRIBUTIONS TO THAUMÄTOXENA. 5 



eine stumpfe, diinne Halbröhre. Sie wird vom Ductus salio- 

 alis durchzogen. Dieses Verhalten zeigt, dass wir es hier 

 mit einem mit dem Hypopharynx identischen Organ zu thun 

 haben.» and compare Wandollbcks' drawings Figs. 18 and 

 20 Pl. 26 witli my textfigures 1 and 2 the conformity is ap- 

 parent. And the fact that the salivary duct opens at the 

 base of the tube is generaJly considered as a conclusive proof 

 of it being the hypopharynx. Thus Packard [Textbook of 

 Entomology, p. 71] writes: »In all insects this organ. . . has 

 a definite location at the end and on the upper side of the 

 labium, and serves to receive at its base the external opening 

 of the salivary duct.» 



rnp 



Textfig. 2. 



Textfig. 2. Rostrum, dorsal view X 310. cl, clypens ; s, sense-organ ; 

 mp. maxillary palp ; 1, labium; rai, mentun ; Ib, labellse) hy, hypopharynx; 

 Ibr, labrum. 



Conseqaently there exists in Thaumatoxena on the upper 

 side of the labium a structure which is the horaologon of the 

 hypopharynx. This structure is neither mentioned nor deli- 

 neated^ by Silvestri, who describes the labium in the fol- 

 lowing way: »Il labro inferiore é costituito da un pezzo 

 mediano, che corre lungo la faccia ventrale del rostro é da 

 due pezzi laterali ad esso uniti, che verso la parte anteriore 

 vanno gradatamente restringendosi un poco ed in corrispon- 



' In his textfig. 16, there is to be seen an acute point betvveen the 

 labellse, which is however not mentioned in the explanatory references. 



