﻿TRÄGARDH, CONTRIBUTIONS TO THAUMATOXENA. 



The labrum (Textfigs. 3 and 4). 



Opposite to the labium and covering its proximal half 

 there is a conical, truncated organ, which has been inter- 

 preted very differently by the authors, Breddin & Börner 

 considering it to be the labrum, whereas Silvestri holds the 

 view that it is composed by the maxillse coalesced with the 

 hypopharynx. 



As to the real hypopharynx I ref er to the statements 

 made above. 



Before entering into the discussion of its morphological 

 value I will describe it, as Breddin & Börner give only a 

 very short description of it and 

 SiLVESTRis' description and drawings 

 of it are not quite correct. 



The labrum (Textfig. 3 & 4.) is 

 pearshaped, its greatest width is bet- 

 ween the first and the second third 

 of its length ; near the truncated tip 

 it is sKghthy constricted. 



The dorsal surface is quite 

 smooth and even in its distal half 

 and does not exhibit any traces, in 

 the shape of sutures, of its supposed 

 coalescence of a pairy organ; in the 

 proximal half there is a tongue- 

 shaped area which is sculptured by 

 very fine radiating striee; of this 

 area only a small part is visible in 

 front of the collar-shaped fold which 

 embraces half of the labrum. 



The anterior end is divided into three lobes of which the 

 two lateral ones are rounded and membranaceous and turn 

 their excavated sides towards each other; they are separated 

 from the median lobe, which is slightly excavated, by two 

 inwardly curWng incisions. 



The median lobe is delineated by Silvestri (1, c. Text- 

 fig. 20, A. H. p. 355) who however seems to identify it with 

 the tip of what he calls the hypopharynx, thus the same as 

 the tip of the median lobe, which is to be seen on ventral 

 view 1. c. p. 357, he says: »Hypopharinx antice subtus trian- 

 gularis, acuta, supra subquadrata apparet, oblique vero in- 



Textfig. 3. Clypeus and 

 labrum, dorsal view. X 310. 



