THE MOUTH-PARTS OF SOME BEETLE LARV2E. 
373 
The Month-Parts of Some Beetle Larvae (Dascil- 
lidae and Scarabaeidae), with especial reference 
to the Maxillulae and Hypopharynx. 
By 
George II. Carpenter, I5.Sf.Lond., TtI.R.I.A., 
Professor of Zoology ; and 
yiabel C. MacDowell, A.R.C.Sc.I., 
Research Student, Royal College of Science, Dublin. 
With Plates 35-37, and 5 Text-figures. 
Introduction. 
The variety of structure that may be observed among the 
larvae of beetles has a most suggestive interest for the student 
of insect transformation. Here, within the limits of the 
single order of the Coleoptera, we find a complete series of 
forms, leading from the active armoured larvae of the Cara- 
bidae, with their elongate feelers and well-developed legs 
with two-clawed feet, to the soft-culicled, legless grubs of the 
Curculionidae and Meloidae — from the campodeiform to the 
eruciform type of insect larva. Since the classical memoir 
of Brauer (’69) on insect transformation, many students have 
laid stress upon the facts of development among the Coleop- 
tera — notably the hypermetamorphosis of the Meloidae, where 
the campodeiform precedes the eruciform type in the life- 
history — in conjunction with the relationship of the Coleoptera 
to the more highly organised insects, such as the Lepidoptera 
and Diptera, whose larvae are always eruciform or vermiform. 
From these premisses they have argued that the active, 
armoured larva must be in the phylogeny of the Insecta 
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