(50) . 



444 0. GORDON HEWITT. 



1862. SCHINER, J. R,. ' Fauna Austriaca : die Fliegen.' 2 vols., Wien. 

 1895. SHARP, D. " Insects," part ii, ' Cambridge Nat. History,' London. 

 1906. TULLOCH, F."The Internal Anatomy of Stomoxys," 'Proc. Roy. 



Soc.' (Ser. B.), vol. Ixxvii, pp. 523531, 5 figs. 

 1906.. WESCHE, W. "The Genitalia of both Sexes in the Diptera, and 



their relation to the Armature of the Mouth," 'Trans. Linn. Soc.,' 



vol. ix, pp. 339386, 8 pis. 



THE UNIVERSITY, 



MANCHESTER. 



EXPLANATION OF PLATES 2226, 



Illustrating Mr. C. Gordon Hewitt's paper on " The Structure, 

 Development, and- Bionomics of the House-fly (Musca 

 domestic a, Linn.). Part I. Anatomy of the Fly." 



PLATE 22. 



FIG. 1. Musea domestica. Female. 



FIG. 2. Anthomyia radicum. Female. 



FIG. 3. Homalomyia canicularis. Male. 



FIG. 4. Stomoxys calcitrans. Female. The halters of this species 

 have been drawn too far back, and in this and the other species the nervures 

 of the wings have been made thicker than they naturally are. 



These figures -are not drawn to the same scale. 



PLATE 23. 



FIG 1. Interior of the head of M. domestica. In this figure the left 

 side of the head capsule and of the proboscis have been removed and the 

 compound eye of the same side, leaving the optic ganglion (periopticou). All 

 the tracheal structures have been omitted. 



a t c. Anterior cornu of fulcrum, a.f.h. Accessory flexor muscles of hau- 

 stellum. ap. Apodeme of labrum. an.n. Antennal nerve. C.G. Cephalic 

 ganglion. di.L Dilator muscles of labium hypopharynx. d.ph. Dilator 

 muscles of pharynx, d.s. Discal sclerite. ex.h. Extensor muscle of hau- 

 stellum. F. Fulcrum. /. Furca. f.c. Fat-cells, f.h. Flexor muscle of 

 haustellum. /./. Flexor muscle of labrum-epipharynx. g.p. Gustatory 

 papillse of oral lobes, k. Hyoid sclerite of pharynx. Ib.n. Labial nerve. 

 Ib.sl. Labial salivary gland, Lhp. Labium-hypopharyux. l.ep. Labrum- 

 epipharynx. mxp. Maxillary palp. ces. (Esophagus, oc.n. Ocellar nerve. 

 ph.n. Pharyugeal nerve, p.c. Posterior cornu of fulcrum. P.O. Periopticon. 

 ps. Pseudotrachea. Pi. Ptilinium. r.d.s. Retractor muscles of the discal 



