POLYPTYCHUS. 165 



Larva : — 



1st instar. Head semi-elliptical, vertex flattened ; body long 

 and thin, horn short, straight, the tip bifid and flattened above 

 and below ; surface of head slightly shining and very minutely 

 reticulate ; body dull ; a transverse row of minute tubercles 

 along each secondary ring ; a conical tubercle placed dorso- 

 laterally on middle of anal flap ; horn smooth and shining ; 

 head and body yellow, horn green. 2nd instar. Head triangu- 

 lar, with a long process on apex of each lobe, the two processes 

 closely appressed except at the tips ; the processes as long as 

 the head ; body long and thin, horn long, straight and bifid ; 

 surface of head dull and covered with minute tubercles, each 

 tubercle bearing a small hair ; body shining ; a transverse row 

 of minute conical tubercles on each secondary ring ; a dorso- 

 lateral line formed of larger tubercles ; the pair of tubercles 

 on anal flap proportionally shorter ; surface of horn smooth 

 and shining ; colour of head yellowish-green, the tubercles 

 paler, the processes dark brown ; body green above the dorso- 

 lateral line of tubercles, yellowish below it ; a black dorsal 

 stripe on segment 2, continuing as a broad ill-defined stripe 

 of dark green to base of horn ; horn black ; true legs 

 black ; prolegs and claspers yellowish. 3rd instar. Little 

 change in shape, surface or colour ; the tubercles on the anal 

 flap disappear. 4&h and 5th instar s. Little change. 



6th instar. Head triangular, vertex rounded, without pro- 

 cesses ; true clypeus about one-third length of head, apex 

 acute, basal angles rounded and tumid ; false clypeus a narrow 

 strip outside true clypeus ; labrum one -half as long as clypeus, 

 three times as broad as long ; ligula semicircular ; eyes with 

 the line joining 1 and 2 at right angles to the straight line 

 joining 3, 4 and 6 ; 1,2 and 3 about one eye-diameter, 

 3 and 4 two diameters and 4 and 6 four diameters apart ; 

 5 four diameters from 4 and three diameters from 6 ; all of 

 equal size. Surface of head slightly shining ; lines of small, 

 low tubercles down face and cheeks, with groups of two to 

 five minute pits between them ; labrum longitudinally corru- 

 gate. Body with segment 2 of greater diameter than head, 

 and segments increasing in diameter to 8, then decreasing 

 slightly to 12. Horn long, straight or slightly down-curved, 

 tapering evenly to a blunt point. Surface of body dull ; a 

 transverse row of minute conical tubercles along each secondary 

 ring ; a dorso-lateral line of much larger pointed tubercles 

 from front margin of segment 2 to base of horn, one tubercle 

 on each secondary ring, each large tubercle flanked by a much 

 smaller one in front and behind. Horn shining and covered 

 with small tubercles. 



Coloration. — Head pale green ; labrum whitish ; ligula 

 dark brown ; basal segment of antenna pale green, other 

 segments reddish-brown ; mandible dark brown. Body 



