ODEZIA ATRATA AND ITS VARIATION. 261 



a transverse row of six short hairs, then, in the same row, at each end, a 

 longish hair, then a very short hair a little hehind, and then another at a 

 slightly lower level, but so far in front as to be on the subsegment in 

 front of the others. These lines of hairs are on about the middle of 

 segments, but the subsegmentation, if such, varies at different eleva- 

 tions, that is, the sulci are short, some dorsal, some lateral, so that 

 to name subsegments is difficult, and would probably be wrong. The 

 head is pale ochreous-green, marked with short streaks of a more 

 olive tint. The 6th abdominal segment is short, the 7th and 8th very 

 short, so that the widely-spaced tubercles of the forward abdominal 

 segments are here crowded together (longitudinally). On the 9th 

 are eight tubercles in line across the segment, the 10th has two dorsal 

 and three marginal on each side. Ventrally is a central white line 

 with a similar one on either side of it. The tubercles beneath are, 

 below V, two about in line with it, and dividing equally the space to 

 middle hne. Well behind iv, three (on each side) in transverse line, 

 each, as it were, corresponding with v and the two below it, but each 

 rather nearer the middle line. 



Dorsal line. 



Ventral line i 



sp 

 . iv ii 



Third instar : In the third instar the larvae reach 12mm. or 13mm. 

 long. They divide into green and brown larvae. The green have a 

 broad green dorsum, with three whitish lines on either side and a very 

 broad whitish lateral line. The brown ones are more variable; some 

 are marked like the green ones, in brownish and ochreous, but some 

 have dark dorsum broadening at middle of segments, or rather giving 

 place to brownish at posterior border of segment, followed by two pale 

 reddish-brown lines, then a nearly black fine line above the pale lateral 

 line. There is also a fine black mediodorsal line. One is really 

 richly-coloured, with eight lines on each side, viz., dark olive dorsal 

 line, ochreous-olive, olive-green, pinkish, olive, pale pinkish-ochreous, 

 black-brown, pale lateral. In one specimen all these lines are present, 

 but the middle of the segment is much darker dorsally, and a similar 

 darkening extends from this dorsal patch to either side, ending 

 narrowly at the pale lateral band; in this specimen, each dorsal 

 tubercle has a pale ring. 



Fourth instar : On April 12th, 1908. A number are now in the 

 fourth instar, though with still a good deal of growing to do. They 

 divide themselves as to colour into a green and a brown set. The 

 green ones are tolerably uniform — they have a darker dorsal line. 

 The marginal flange is white. The green ones vary most in this 

 white band, sometimes it is very white, at others it is almost green, 

 though paler than the other portions. Its lower border is sharply 

 defined, but it fades a little upwards into green, much like the white 

 stripes in Enchloc and similar Pierid larvae. From its lower margin to 

 the dorsal line are six bands, an upper one, broad, of ground colour, 



