﻿8 ARKIV FÖR ZOOLOGI. BAND 4. N:0 10. 



spect ut appendix uncinata distincta.» This is however not 

 the case, as my textfig. 4 plainly shows. 



The ventral side is deeply excavated in the middle; the 

 groove is posteriorly very narrow, the strongly chitinous and 

 slightly downwardly bent edges of the labrum nearly meeting, 

 but it widens considerably towards the tip of the labrum; 

 the groove is separated from the rest of the surface by an 

 distinct sharp edge which bends in an even curve outwards 

 and is continued in its distal part by the exteriör edge of 

 the lateral lol)es. 



Textfig. 4. 



Textfig 4. Clypeus and labrum, ventral view. X 620. cl, clypeus ; 

 Ibr, labrum ; ep, epipharynx. 



In the bottom of the groove there is a pair of long pa- 

 ralell chitinous bars quite coalesced with its floor. The bars 

 reach as far as to the ventral anterior edge of the labrum 

 and seem to branch off into two short bars each, which form 

 both the edges of the median sharp tooth of the ventral 

 lobe and the inner edges of the lateral teeth. 



The labrum, which is very remarkable through its great 

 development, resembles very much that of the Stethopathidce ^ 

 both in shape and size. 



^ Wandolleck (1. c. p. 419) says expressly that he uses the terms 

 labium and labrum only in order to give some name to the structures in 

 question, and that he cannot say whether they are really homologuous to 

 the labium and labrum. 



