688 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
If one dissects away the cuticle of the head of an old larva 
about to pupate, the pupal mouth parts will be found formed 
fairly within the old larval ones, and thus in perfect corre- 
spondence with them. Rather it would be truer to say that 
they are apparently the transformed larval parts minus the 
to-be-shed larval cuticle. This is shown in Fig. 3, in which 
the larval cuticle of the right-hand half of the head (including 
the whole of the labium) has been dissected away, exposing the 

Fic. 5. 
Fic. 4.— V l aspect of head of adult male Cor-ydali: ta. lb., labrum; md., mandible; 
mx., maxilla; m2z.p., maxillary palpus; ga., galea; Za., lacinia; li., labium; Z., labial 

Sa 
pus. 
Fic. 5. — Ventral aspect of head of pu -ydali: ta, the pupal body wall being dis- 
sected away on right side (in figure), showing formi 
i al 

ng imaginal head and appendages. 
maxilla; /./i., pupal labium; #.4., pupal body wall 
, imaginal mandible; i»x., imaginal maxilla; 7./é., imaginal labium; 
ih., body wall of imaginal head. 
still soft, unchitinized pupal cuticle, while the left side of the 
head is still wholly larval. From the right pupal mandible has 
been slipped the larval mandibular sheath, from the right pupal 
maxilla has been slipped the larval maxillar sheath, and from 
the whole pupal labium has been removed the larval covering. 
But the slight changes in outline and character of the pupal 
mouth parts are plainly apparent, while the identity of larval and 
pupal mandibles, maxillæ, and labium is unmistakable. There 
_is yet no apparent difference in the mouth parts of the sexes. 

