(102) 



542 0. GORDON HEWITT. 



FIG. 10. "Nymph" of M. domestica dissected out of pupal case about 

 30 hours after pupation. 



an. Swellings of nymphal sheath marking bases of antennae, ex. Coxa of 

 leg. 16. Labial portion of proboscis sheath. Ibr. Labral portion of same. 

 n.sp. Spiracular process of nymph, w. Wing in nymphal alar sheath. 



FIG. 11. Head of "nymph" (about 48 hours after pupation). Enclosed 

 in nymphal sheath. To show the development of the imaginal proboscis. 



an. Antenna, c.e. Compound eye. fac. Facialia. lab. Labrum. mx.p. 

 Maxillary palp. o.L Oral lobe. 



FIG. 12. Posterior end of larva in the second stage (2nd instar). 

 an. Anus. p.sp. Posterior spiracle. 



FIG. 13. Cephalopharyngeal skeleton of the first larval instar ; the out- 

 line of the pharyngeal mass is shown in dotted lines. 



t.s. T-shaped sclerite of the left oral lobe. Other lettering as in Fig. 4. 



FIG. 14. Longitudinal section through the surface of one of the oral lobes 

 of mature larva to show the food-channels. 



ch. Food-channel, ct. Outer layer of cuticular integument, ct'. Inner 

 layer of the same. hy. Hypodermis. 



FIG. 15. Pupal case of M. domestica from which the imago has emerged, 

 thus lifting off the anterior end or "cap" of the pupa; ventro-lateral aspect. 



a.sp. Remains of the anterior spiracular process of larva, l.tr. Remains of 

 the larval lateral tracheal trunk, n.sp. Temporary spiracular process of 

 nymph, p.sp. Remains of the posterior spiracles of larva. 



PLATE 31. 



FIG. 16. Muscular system of the body-wall of the right side. The straight 

 dorsal line is the median dorsal line of the body, and the curved ventral line 

 is the median ventral line. 



I XIII. Body segments, an.l. Anal lobe. an.m. Anal muscle, c.r. 

 Cephalic retractor muscle, d.v. Dorso-ventral muscle of the terminal seg- 

 ment, ex.d.l. External dorso-lateral oblique recti muscles, i.l.o. Internal 

 lateral oblique muscle, in.d.l. Internal dorso-lateral oblique recti muscles. 

 l.i.m. Lateral intersegmental muscle, l.m. Lateral muscles, l.tr. Branch of 

 lateral tracheal trunk communicating with the anterior spiracular process. 

 l.v.l. Longitudinal ventro-lateral muscles, p.sp. Posterior spiracle, s.d. 

 Stomal dilators, v.c.r., v'.c.r. Ventral cephalic retractor muscles, v.l.o. 

 Ventro-lateral oblique muscle, v.o. Ventral oblique muscle. 



FIG. 17. Oblique section through the pharyngeal mass of the larva in the 

 direction and at the level shown by the line a.b. in Fig. 19. (Camera lucida 

 drawing.) 



e.o.m. Elongate oblique pharyngeal muscle. Lp. Lateral pharyngeal 



