The Moths and Butterflies 
359 
posed of the two greatly elongate maxillae, so apposed that a groove on the 
inner face of one fits against a similar groove on the inner face of the other, 
the two thus forming a perfect tube (Fig. 510). This sucking proboscis, when 
extended, may protrude five or six 
inches, as in some of the sphinx- 
moths, or only a fraction of an inch, 
as in the small moth “ millers,” but 
when not in use it is so compactly 
coiled up, watchspring-like, under 
the head, and so concealed by a 
pair of hairy little tippets (the labial 
palpi) which project up on each 
side of it thatpt is nearly invisible. 
Of the other mouth - parts, the 
upper lip (labrum) and under lip 
(labium) are greatly reduced and 
are not movable and flap-like as in 
most insects, while the mandibles 
are either wholly wanting or, as in 
the sphinx-moths and some others, 
represented only by small immov¬ 
able functionless rudiments. The 
palpi of the maxillae are also either 
wholly wanting or present as mere 
rudiments. The foregoing descrip¬ 
tion of the mouth-part conditions 
is true for the great majority of 
Lepidoptera, but among the lowest 
(oldest or most generalized) moths 
some interesting examples of much 
less specialized conditions occur. 
Indeed in one family of minute 
moths, the Eriocephalidae, all the 
usual parts of a typical insect 
mouth are present and in a condi¬ 
tion fitted for biting and chewing 
and in all ways wholly comparable 
with the condition in such biting insects as the locusts and beetles; the 
mandibles are movable and truly jaw-like, the maxillae short and also 
’ jaw-like and provided with several-segmented palpi, while both labrum 
and labium are truly lip- or flap-like and fully movable, the labium 
bearing 3-segmented palpi. Between this most generalized condition 
Fig. 507.—A trio of apple tent-caterpillars, 
larvae of the moth Clisiocampa americana. 
These caterpillars make the large unsightly 
webs or tents in apple-trees, a colony of 
the caterpillars living in each tent. (Photo¬ 
graph from life by Slingerland; natural size.) 
