INTEODUCTION. 5 



elongate, compressed laterally ; the anal and genital apertures at its 

 extremity. 



(&.) 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 clypcus. Eyes not 

 compound, but tubercular and simple (skmmata), 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 maxillae 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 maxillas 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 thi"ee 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. 

 Regional boundaries of head, thorax, and abdomen distinctly defined 

 by the sutures of the investing membrane (thcca). 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. 



