comparative Chcetotaxy. 



503 



The appended figure is borrowed from Prof. Mik (/. c.) ; 

 p is the prothorax, s the scutellum. 



A. Sutures. 



Dorsoj^leural suture. — It runs from the humerus to the 

 root of the wing, and separates the mesonotum (or 

 tergum) from the pleura. (No. 1 in the figure). 



Sternopleural suture. — Horizontal suture below the 

 dorsopleural and parallel to it ; it separates the meso- 

 pleura from the mesosternum. (No. 2 in the figure). 



Mesopleural suture. — Euns from the root of the wing 

 downwards, and separates the mesopleura from the 

 pteropleura. (No. 3 in the figure). 



B. Portions of the Pleura. 



Mesopleura, square piece in front of the root of the 

 wing, and between the dorsopleural and sternopleural 

 sutures. It answers to the anterior lateral plate of the 

 mesothorax of Lowne (Anat. of the Blowfly, Plate 5, 

 f. 5), and to the parapteron of Hammond ('On the 

 Thorax of the Blowfly,' Journ. Linn. Soc, xv., pi. i.). 

 (a of the figure). 



Pteropleura, situated under the insertion of the wing, 

 and behind the mesopleural suture. It is the posterior 

 lateral plate of the mesothorax of Lowne, and the epi- 

 sternum of the mesothorax of Hammond {I. c). (h of 

 the figure). 



Sternopleura ; it is that portion of the mesosternum 

 which, from its position, forms a part of the pleura (c of 

 the figure). It is convenient to have a separate name 

 for it, as very important bristles are inserted upon it, 

 although it is not separated by any suture from the 

 middle portion of the mesosternum. 



Hypopleura, a distinct piece above the two last pairs 

 of coxse, and behind the sternopleura, from which it is 



TRANS. ENT. soc. LONP. 1884. — PART IV. (DEC.) 2 M 



