84 



Proceedings of the Royal Irish Academy. 



Fio. 



12. 



13. 



14. 



15. 

 10. 



17. 



IS. 



Plate X — continued. 



H. ' s, Fourth-stage larva, front end, showing position of anterior 

 spiracles (a. sp.) in relation to mouth (m.) and suture (p. g.) bounding 

 puparial lid. x 10. 



Pi LTE XI. 



B bovis. Fourth-stage larva. Left anterior spiracle, x 300. 



v. /., ventral lip of spiracle ; p. •/. suture bounding puparial lid. 

 Anterior spiracle in tangential section, through spiracular 



ity. 

 The - per in the body-wall. 



•.ity. 

 spiracular trachea with solid 

 chitinoua core and avelope of secondary cuticle x 700. 



level in the body-wall, showing corn- 

 plet a ary cuticle [ct. 2 [rounding 



normal secondary cuticli - b) end 



chitinoua core d 1 . 



Other I "10. 





- 



XII. 



Portion of front extension of 

 gitudinal trunk, forming anterior spiracular trachea, showing 



with chitinoua core [ct. 1) to 

 u;li normal spiral thickening, ■ 200. 

 if right longitudinal tracheal trunl x 30. 



. - : _ ■ 



Plate XIII. 



.7 Fourth-stag Photograph Bhowing piece of body-wall 



wit! ir lateral spiracle I lected with air-tube system 



■ 



22. ] longitudinal trunk with branches of fourth 



abdominal segment in connexion with the third lateral spiracle, x 15. 



(Photographs by EL Pattison.) 



