PROCEEDINGS 



THE ROYAL IRISH ACADEMY 



PAPERS READ BEFORE THE ACADEMY 



I. 



ON THE MOUTH-PAETS OF SOME BLATTID^. 

 By JOSEPH MANGAN, B.A., A.E.C.Sc. 



[communicated by PEOFESSOR G. H. carpenter, B.SC, M.R.I. a.] 



(Plates I.-III.) 



[Read Apkil 13. Ordered for Publication April 15. Published May 23, 1908.] 



Cockroaches occupy a peculiar position amongst insects. The comparative 

 ease with which they may be dissected, the readiness with which they 

 can be procured, together with generalized structure, mark them out 

 as the " type " ])ar excellence of the Hexapoda, furnishing as they do 

 a most suitable ground-work for further systematic study of the group. 

 Hence it is not surprising that some of the common species have been 

 the subject of many careful descriptions in text-books, and have been 

 employed therein for comparison with the higher members of the class. 

 In this last respect, the mouth-parts are possibly of greatest interest, 

 yet they appear to have received but little detailed study. The precise 

 contour of the brain has even been recorded by piecing together the drawings 

 of consecutive sections ; but referring to the maxillae or labium the student 

 will experience a very certain sense of dissatisfaction, both diagrams and 

 descriptive matter showing the scant attention accorded to these parts. To 

 appreciate the novel views of Hansen ('93) as to the jointing of the maxillae 

 and his belief in the presence of homologues of the Thysanurau maxillulse in 

 some Orthoptera, a more careful examination is necessary. 



R. I. A. PEOC, VOL. XXVII., SECT. B. \_B'\ 



