260 Illinois State Lahoratory of Natural History. 



Egg [Fig 58].— Leng-th 1.1 mm., greatest diameter 

 .27 n)m. Pale yellowish when first laid, becoming black- 

 ish before hatching; smooth, fusiform, somewhat atten- 

 uated towards each end ; laid in irregular oval rounded 

 convex clusters about one third of an inch long, con- 

 taining on an average about five hundred eggs. 



Larva, newly hatched. — Length 1 mm. Broad and much 

 flattened ; blackish ; last segment nearly as broad as 

 long; plumose hairs as long as the segment, anal slit 

 about half its length; head similar to last segment in 

 Bhape and nearly as large, remaining segments very 

 much broader than long, each half as long as last 

 segment, and about twice as wide at middle of body, 

 lateral margins seriulate; no distinct coloration. 



Larva, mature [Fig. 59]. — Length 20-30 mm., usually 

 about 25 mm., greatest width (fourth or fifth segment) 

 4.5-5 mm.; tenth segment 2.5-3 mm. wide; last, at base, 

 2 mm., its length 2.5-3 mm., or twice the length of anal 

 slit. Elongate-lanceolate, depressed, tapering slight- 

 ly from apex of fifth segment; fuscous brown, grayish 

 luteous when dry, becoming blackish previous to later 

 moults, striped above and below with light yellowish or 

 greenish yellow. Upper surface with lateral margins and 

 six vittse pale. Of the intervening seven dark lines, the 

 middle one on each side is very broad and generally the 

 darkest, its inner edge quite straight and usually dis- 

 tinct, and the body more or less angulate along this 

 edge. The median dark line widens greatly on the disk 

 of each segment, causing the narrow pale vitta on each 

 side to curve outwardly, and is somewhat distinctly V- 

 shaped and confluent anteriorly with the adjoining dark 

 lines on segment 3, less so on 4, but not especially 

 daiker at these points. The next pair of pale vittse, 

 lying just within the angulation, varies greatly — some- 

 times very indistinct, but generally broad and in sharp 

 contrast with the dark band exterior to each; the space 

 between the angulations often forms a broad conspic- 

 uous pale dorsal stripe with three dark lines near mid- 



