542 C. GORDON HEWITT. 
Fie. 10.—“‘ Nymph” of M. domestica dissected out of pupal case about 
30 hours after pupation. 
an. Swellings of nymphal sheath marking bases of antenne. ca. Coxa of 
leg. 7b, Vabial portion of proboscis sheath. 7/67. Labral portion of same, 
n.sp. Spiracular process of nymph. w. Wing in nymphal alar sheath. 
Fie. 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. (ab. Labrum. mz.p. 
Maxillary palp. 0.2. Oral lobe. 
Fig. 12.—Posterior end of larva in the second stage (2nd instar). 
an. Anus. p.sp. Posterior spiracle. 
Fie. 138.—Cephalopharyngeal skeleton of the first larval instar; the out-- 
line of the pharyngeal mass is shown in dotted lines. 
¢.s. T-shaped sclerite of the left oral lobe. Other lettering as in Fig. 4. 
Fic. 14.—Longitudinal section through the surface of one of the oral lobes 
of mature larva to show the food-channels. 
ch. Food-channel. cf. Outer layer of cuticular integument. cd’. Inner 
layer of the same. Ay. Hypodermis. 
Fic. 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. 7.47. Remains of 
the larval lateral tracheal trunk. .sy. Temporary spiracular process of 
nymph. p.sp. Remains of the posterior spiracles of larva. 
PLATE 31. 
Fie. 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. az./. Anal lobe. az.m. Anal muscle. e.r. 
Cephalic retractor muscle. d.v. Dorso-ventral muscle of the terminal seg- 
ment. ex.d./. External dorso-lateral oblique recti muscles. 7./.0. Internal 
lateral oblique muscle. 727.d./. Internal dorso-lateral oblique recti muscles. 
li.m. Lateral intersegmental muscle. J/.m. Lateral muscles. J/.¢7. Branch of 
lateral tracheal trunk communicating with the anterior spiracular process. 
lvl. Uongitudinal ventro-lateral muscles. p.sp. Posterior spiracle.  s.d. 
Stomal dilators. v.¢7., v'.c.. Ventral cephalic retractor muscles. ./.0. 
Ventro-lateral oblique muscle. ¥v.o. Ventral oblique muscle. | . 
Fie. 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. Hlongate oblique pharyngeal muscle. /.p. Lateral pharyngeal 
