57 



Labium (Second Maxillae) of the Paraneuroptera 

 (Odonata). 



By W. J. Lucas, B.A., F.Ti.^.—Read November dth, 1922. 



In view of the fact that a certain proportion of our members are 

 not entomologists some apology is perhaps necessary for introducing 

 a subject that does not come within their range of interest. To the 

 entomologists I must apologise for bringing forward so many facts 

 with which they are already well acquainted. Both, I hope, will 

 pardon me. 



At the present time it is fairly well agreed that the head of an 

 insect is composed of seven segments (somites, arthromeres), whose 

 division lines (sutures) are, however, none too easily made out. 

 They are : — (1) the Ocular, bearing the eyes and ocelli ; (2) Anten- 

 nal, bearing the antennae ; (3) Second Antennal, usually without 

 appendages (but in Campodea and L'Dllembola rudimentary append- 

 ages are present corresponding to the antennae in Crustacea) ; (4) 

 Mandibular, bearing the mandibles ; (5) Maxillular, with the 

 maxillulae, when these appendages are present ; (6) First Maxillary, 

 bearing the first maxillae ; (7) Second Maxillary, or Labial, with 

 the second maxillae, or labium as they are more usually styled, at 

 any rate in the Paraneuroptera. 



