
No. 429] | THE MOUTH PARTS OF INSECTS. 691 
been able, however, to get series showing plainly the later 
steps of the development of the imaginal parts within the head 
of old larva. The developing imaginal parts, their definitive 
outlines already so strongly indicated as to make them recogniz- 
able (apart from their position), lie within the corresponding 
parts of the larval head (Fig. 8), imaginal mandibles with their 
tips within the larval mandibles, 
imaginal maxilla with their two 
terminal lobes lying partly within 
and corresponding to the single 
terminal lobe of the larva, and 
imaginal palpi lying almost wholly 
within the larval palpi, and finally 
imaginal labium lying in the base 
of the larval labium. All of the 
forming imaginal parts are plainly 
seen to be folds or evaginations of 
the forming imaginal derm layer, 
which shows in sections as a con- 
tinuous broad cellular line lying 
just underneath the larval integ-  ilary palpus; ZZ, larval labium; 24. 
ument. imaginal labium 
Thus in Anatis we have practically the same conditions of 
development of the imaginal mouth parts within, and corre- 
sponding to, the larval mouth parts as we found in Corydalis. 

LEPIDOPTERA. 
Among the Lepidoptera we find a great range in degree of 
specialization of the mouth parts. In Eriocephala and Microp- 
teryx, as described by Walter! and myself,? the mouth parts 
are really of the biting type, the mandibles being short, heavy, 
and dentate, true jaws, the maxillae showing a cardo, stipes, 
short galea, and lacinia, and long six-segmented palpus, and 
the labium being liplike, with plainly distinguishable submentum 
! Walter, A. Beiträge zur Morphologie der Schmetterlinge, Jenaische Zeitschr. 
Í- Naturwiss., vol. ioe (1885), pp. 751-807 
2 Kellogg, V. L. The Berrea Parts of the Lepidoptera, Amer: Nat., vol. v 
(1895), pp. 546-556, PI. X 
