INTEODUCTIOK 
5 
elongate, compressed laterally ; the anal and genital apertures at its 
extremity. 
(b.) Larva (or Caterpillar). 
Worm-like, cylindrical or sub-cylindrical, presenting thirteen seg- 
ments (taking the head as the first) ; the integument generally softer 
and more elastic than in the Imago. Head hard and horny, divided 
into two more or less distinct lobes by a frontal depression ; inferiorly 
these lobes are divergent, between them lying the clypeus. Eyes not 
compound, but tubercular and simple (stcmmata), usually six on each 
side, situated in a ring at the lower end of the cephalic lobe. Antennae 
horny, small, short, conical, three- or four-jointed, situated inferiorly, 
between the simple eyes and the base of the mandible. Labrum of 
moderate size. Mandibles large, very hard, strongly and acutely 
toothed on their inner meeting edges. Labium and maxilla united ; 
the former lying between the latter, and presenting at its extremity a 
small tubular organ (spinneret) containing the common duct of the two 
silk-glands, and a pair of very minute palpi ; the maxillae small, much 
softer than the mandibles, conical, three-jointed, adapted for prehension 
(not mastication), bearing minute palpi near their extremity. 
Legs (true) six, borne on the three segments next succeeding the 
head (which answer to the thorax of the perfect insect), short, horny, 
cylindrical, composed of five short joints, of which the terminal one 
(tarsus) forms an acute curved claw. Posterior to the sixth segment, 
a series (two to five pairs) of highly retractile, stout, fleshy " claspers " 
or pro-legs, fringed at their extremity by numerous small hooked 
bristles.-^ Breathing-pores (spiracles) lateral, inferior, a pair on each 
segment except the head, and the third, fourth, and thirteenth. 
(c.) Pupa (or Chrysalis). 
Elongate, more or less sub-conical, blunt anteriorly, and pointed 
posteriorly ; closely invested by a hard membrane, which binds the 
developing limbs of the future Imago closely to the breast and basal 
part of the abdomen, but leaves their form more or less defined ; 
mummy-like, quiescent, only 'the abdominal segments capable of motion. 
Eegional boundaries of head, thorax, and abdomen distinctly defined 
by the sutures of the investing membrane (theca). Abdomen consist- 
ing of nine segments, gradually decreasing to the last, which is more 
or less acutely pointed. Each abdominal segment except the last 
bearing a pair of lateral spiracles. 
The Eggs (ova) laid by Lepidoptera are very variable in form, 
being found globular, pyriform, regularly ovate, melon-shaped, &c., 
and the shell or external membrane is very commonly distinguished 
^ The seventh, eighth, and ninth segments may want pro-legs (as in the Geometer larvae), 
and very rarely the thirteenth or last segment (as in the Bombycid Dicranura), but the maxi- 
mum number is five pairs, and the minimum two pairs. The fifth, sixth, eleventh, and 
twelfth segments never possess pro-legs. 
