﻿ARKIV FÖR ZOOLOGI. BAND 4. N:0 10. 



Furthermore it is impossible to perceive how such a 

 thorough chauge as that from the sucking type of mouth parts 

 of the Hemiptera to that of Thaumatoxena could possibly 

 have taken place and moreover in a comparatively speaking 

 so short time as what has elapsed since the beginning of the 

 tertiary epoch. Because even in the most highly modified 

 termitophilous insects, as for instance in the Aleocharini, the 

 original type of the mouth-parts can easily be traced. 



SiLVESTRi on the other hand considers Thaumatoxena to 

 be a Dipteron, closely related to the Phoridce and more closely 

 still to the Stethopathidoe. Apparently he has however not 

 made a detailed comparison of the mouth-parts of the two 

 groups, a cireumstance for which the bad condition of his 



only specimen very likely accounts. 

 Consequently he has interpreted 

 the mouth-parts of Thaumatoxena 

 in a way, which if it were correct, 

 would oontradiot his opinion as 

 to the close relation of Thauma- 

 toxena and the Stethopathidos. 



When describing the mouth- 

 parts I begin with the labium 

 about the interpretation of which 

 the authors do not dissagree. 



Breddin and Börner des- 

 cribe it in the generic diagnosis 

 as follows (p. 85): 



»Labium (Unterlippe, Riissel) 

 zweigliedrig, das zweite Glied 

 (= Labialpalpus) zweitheilig, seine 

 beiden Theile nur durch arthrodiale Membran verbunden; 

 die Innenseite mit einer (von einem oberflächlichen Chitinge- 

 riist gebildeten) Speichelrinne, deren Miindung zwischen den 

 Palpengliedern liegt. Hypopharynx reducirt» and in the 

 diagnosis of the species they add: >>Zwischen den beiden 

 Endgliedern ist am Ende der Labialrinne eine knopfartige 

 Verdickung vorhanden die in eine stumpfe Spitze endigt.» 



If .we compare this description with that which Wan- 

 DOLLECK gives of the labium of one of the genera of the 

 Stethopathidoe: »In der Unterlippe liegt nun, von der Anhef- 

 tung des Mentums bis in die Schenkel der Ligula ziehend. 



Textfig. 1 

 view. X 310. 



Textfig. 1. 



Labium, ventral 



