90 APPENDIX 



A, V, the Face is the region above the so-called mouth and be- 

 low the antennas; the ridges bounding the face on each side 

 are (I) the Facialia ; here are (2) the Facial Bristles; (3) the 

 Mystax (pi. VI, fig. 28) is peculiar. 



A, VI, the Cheeks, spaces at the sides between A, II and A, V(i). 

 A, VII, the Jowls, parts below A, VI and the so-called mouth. 



A, VIII, the Mouth, more or less of a cavity into which (3) the 

 Proboscis (the jointed sucking trunk) can be sometimes 

 partly withdrawn; the proboscis has a basal joint called the 

 Rostrum (a snout) ; the other joint is called the Haustellum 

 (a pump) and has the tip variously adapted as for mere sur- 

 face suction, or for deep insertion, or for piercing. (I) the 

 Peristome is the region surrounding the mouth ; (2) the Vi- 

 brissae are strong bristles close to the sides of the mouth, or 

 A, V(I); (4) the Palpi, two feelers (or perhaps smelling 

 organs) attached to the proboscis. 



A, IX, the Back of the Head; here (I) Post-orbital Bristles are 



sometimes found, that is to say, behind the eyes, A, II. 



B = the Thorax, the middle portion of the fly bearing the organs 

 of locomotion. 



B, I, the Dorsum. The diagram on plate VI, .//.;'. 40 illustrates 



the upper surface of this region; this part is bounded in 

 front by (a) the Neck; behind by (b) the Scutellar Suture 

 (15) or Seam; at the sides by (c) the Dorso-pleural Sutures 

 (9-9) running from the front corners to the front of the 

 Wing Bases; by (d) the Wing Bases (10- 10) ; and by (e) the 

 Scutellar Bridges, which are ridges (il-ll) running with 

 right and left inclines to ihe root of (6) the Scutellum. 

 The Dorsum is crossed by (8) the Dorsal Suture, behind 

 which are the Alar Regions (5~5); here on each side is a 

 ridge (12-12) the Alar Frenum; rows of minute bristles on 

 the centre are termed Acrostichal. 



B, II, the Sides, or Pleuras, specified separately in connection 

 with 



B, III, the Brest, or Sternum; (I) the Prothorax is below the 

 shoulder and above the fore-leg ; (2) the Meso-pleura is 

 contiguous to the prothorax and the shoulder; here in the 

 upper front corner is the "Stigma," a prominent respiratory 

 orifice, below which the large Stigmatical Bristle may be 

 found ; the (3) Ptero-pleura is below the wings and behind 

 the meso-pleura; (4) the Meta-pleura is "a more or less 

 tubercular piece below the region between the root of the 

 wing and the haltere"; (5) the Sterno-pleura is above the 

 middle leg and below the Sterno-pleural Suture, where it 



