34 
10. 
ll. 
12. 
Dr. D. Keilin.on the Larve &c. of 
. Embryo in the egg curved. 
. The larvz move ina serpentine 
manner, or by means of very 
active mandibles. 
. The segments of the body are 
separated hy intercalary rings 
(Pl. V. fig. 38). 
. The larval head with a pair of 
. tentorial rods (Pl. IT. tigs. 1 
& 2, ¢..) similar to those of 
the larvee of Zrichocera. 
. Antenne with a special sensory 
organ (Pl. V. fig. 37, 0.s.), 
corresponding to the —bell- 
shaped papilla of many other 
dipterous larvee (for instance, 
those of Ditomyia and all 
eyclorhaphous Diptera) and 
with some small -cylindrical 
apillee. 
. Mandibles (Pl. V. figs. 35 & 
36) show two distinct por- 
tions: basal portion (6.p.) 
with an internal hook (A.), 
and terminal or apical por- 
tion (t.p.) which is more 
chitinised, ending in three 
teeth and bearing two brushes 
of brown sete. 
. Maxille fleshy and soft; the 
maxillary palp (figs. 1 & 2, 
ap.) broad, thick, trans- 
parent, bearing two groups of 
sensory papille (a. and 6.); 
the internal part of the 
maxillee (m.2.), hesides a few 
sensory organs, bears nume- 
rous long sete. 
Labrum with two mid-ventral 
protuberances covered with 
hairs (figs. 1 & 2,27. & pr.) 
and a small comb-shaped 
plate (c.m.) on each side of 
posterior protuberance. 
Labium well developed and 
with distinct labial palps 
(Z.p.). : 
The thoracic sensory organs 
which are the remains of the 
thoracic legs are composed 
of four hairs (two long and 
two short). 
3. Embryo straight. 
4, The larval movements 
worm-like. 
are 
5. No distinct intercalary rings 
(Pl. LL. tig. 3); only some 
larvee——-for instance, those of 
Ceroplatus — have the seg- 
mentation of their abdomen 
masked by superadded trans- 
versal folds. 
6. Head without tentorial rods, 
7. Antenne either elongated as in 
Bolitophiia (Pl. Il. fig. 4, 
A.n., and fig. 13) or reduced 
to a flat, wide, non-chitinised 
surface bearing some very 
small sensory papillee. 
8. Mandibles (figs. 5 & 7) flat- 
tened, strongly chitinised, and 
with their internal margin 
toothed. 
9. Maxille (PI. III. figs. 10, 11, 
12) flattened and strongly 
chitinised, with their internal 
margin (m.a.) toothed, like 
those of the mandibles. The 
maxillary palps (m.p.) are 
very much reduced. 
10. Labrum (figs. 6 & 8) without 
mid-ventral protuberances 
and without comb-shaped 
plates. 
11. Labium reduced and not visible 
trom exterior. 
12. Thoracic sensory organs com- 
posed of four hairs of equal 
length (fig. 9). 
