﻿TRÄGÅRDH, CONTRIBUTIONS TO THAUMATOXENA. 3 



The labium, which Breddin & Börner state to be build 

 as in Corixa, is also shaped nearly exactly like the labium 

 of the Stethopathidce. 



The differences between Thaumatoxena and Corixa are 

 according to Breddin & Börner the following : »Ganz eigen- 

 artig bleibt (1) das Fehlen der Stech borsten, (2) die relative 

 Selbständigkeit der Labialpalpenglieder, (3) die Stellimg der 

 Fiihler zwischen den Augen, (4) die Fiinfgliedrig der Tarsen, 

 (5) die Lage der Mesothorakalstigmen und (6) die Unter- 

 driickung der Ubrigen Stigmenpaare (vielleicht mit Ausschluss 

 der metathorakalen?), (7) die Einbeziehung des siebenten Ab- 

 dominalsegment in den Anogenitalapparat, (8) die Besonder- 

 heiten der Segmentierung und (9) die allgemeine Körper- 

 gestalt.» 



All these characters except 5, 6, 8 and 9, which probably 

 are adaptions to the termitophilous life, Thaumatoxena shares 

 with many Diptera and especially with the Stethopathidce. 



The aberrant characters Breddin & Börner consider 

 to be, partly the result of a thorough, one-sided adaption to 

 the termitophilous life, partly of an old phylogenetic value. 

 »Vielleicht haben wir in Thaumatoxena einen selbständigen 

 Abkömmling der urspriinglichsten Auchenorrhynchen {Homo- 

 ptera) vor uns.» This view necessitates the assumption that 

 this singular and aberrant type of Hemiptera has been pre- 

 served owing to its having acquired termitophilous habits. 

 But as the Hemiptera are a much older group than the ter- 

 mites, fossils of them having been found alreadv in the Per- 

 mian epoch, whereas the termites have not been found earlier 

 than in the tertiary epoch, the view of Thaumatoxena being 

 an Hemipteron necessarily results in a contradiction. 



Becäuse one can scarcely presume, that a small branch 

 of the most primitive Homoptera should have persisted through 

 the successive epochs until the tertiary and then suddenly 

 should become extinct with the exception of the ancestor of 

 Thaumatoxena, which associated itself with the termites. 



It is in this connection also worth mentioning, allthough 

 it is of course no proof in itself, that up to the present no 

 real termitophilous hemiptera have been found, a fact which 

 cannot be a mere coincidence, but seems to suggest some 

 profound causes, either that they lack the ability of adapting 

 themselvs or that they are to offensive. 



