366 THE buttekflip:s of new England. 



Dimorphic forms, p. p. c-akgexteum. Has the ground tint of the upper surface 

 of all the wings concolorous. 



p. p. L-ARGENTEUM. Has the basc of the hind wings obscured above with dusivy tints. 

 It difi'ers from the preceding, so far as the markings are concerned, but very little and, 

 as there, the sexes do not differ; the fore wings are identical on both surf aces ; the 

 upper surface of the hind wings is more heavily infuscated on the outer half, reach- 

 ing further toward the base, but never concealing the distinctness of the black spots 

 of the middle of the wings ; the submarginal series of fulvous spots are almost wholly 

 though never fully obliterated; on the under surface, the L-shaped mark at the tip of 

 the cell is as a rule slenderer than in c-argenteum, being of about the width of the 

 nervules in this part of the wing, although individuals of the former occasionally have 

 it as indistinct as here, and the longitudinal limb is always much shorter than the 

 other, by which it approaches more the exact form of an L or is sometimes wholly 

 obliterated. 



Egg (64 : 25). Laminate ribs ten in number, commencing below at the rounded under 

 surface and continuing of nearly the same height over the lower half of the egg, 

 leaving a free space on the summit, .2 mm. in diameter; the ribs are .02 mm. in thick- 

 ness and on the sides are .025 ram. high, while on the summit their elevation increases 

 to .07 mm. ; surface smooth, glistening, broken into cells by straight, exceedingly 

 delicate, scarcely raised cross lines, .02 mm. apart, visible on the ribs only on the upper 

 part of the egg. Color pale greenish, the ribs pellucid. Height including the ribs, 

 .95 mm. ; breadth, .81 mm. 

 Edwards describes the egg as having eight or nine ribs ; all tliat I counted had ten. 

 Caterpillar. First stage. Head shining piceous, hairs and ocelli black ; the mouth 

 parts, in part at least, pale. Body grass green, the segments very pale green anteriorly, 

 tinged with reddish brown posteriorly ; warts and hairs black ; spiracles blackish fus- 

 cous ; legs blackish fuscous ; prolegs greenish yellow tipped with fuscous. Length, 

 3 mm. 



Second stage. Head (78 : 47) very dark castaneous with blackish hairs arising from 

 the tubercles. Body dark olivaceous green, the mammiform leases of the spines and 

 the last four or five segments marked with dull, dirty, yellowish orange; the oblique 

 streaks of the adult are barely discernable. Spines blackish brown, the spinules 

 emitted mostly near the summit; the latter terminate with long, nearly straight, black- 

 ish hairs, and the main spine is surmounted by a longer hair; on the second and third 

 thoracic segments a minute, subdorsal wart gives rise to an erect blackish hair. Spira- 

 cles fuscous. Legs greenish yellow at base, beyond fuscous; prolegs greenish yellow, 

 fuscous at tip. Length, 6 mm. 



Third stage. Head (78 : 48) blaclvish, marked to a greater or less extent with spots 

 and blotches of obscure reddish orange ; the spinif orm tubercles are blackish or red- 

 dish at base, white at tip, surmounted by a black hair; ocelli orange in a black area; 

 mouth parts mostly black. Body purplish fuscous, with two narrow, transverse, dull 

 lemon yellow bands at the posterior border of the segments ; the mammiform eleva- 

 tions bearing the spines are dull reddish orange, connected with the anterior border of 

 the segments by short patches of the same color; spines usually dark purplisli black, 

 sometimes luteous ; the subsidiary spinules generally blackish but sometimes luteous. 

 Spiracles black, broadly annulated Avith luteous, which is itself sometimes narrowly 

 bordered without with Avhitish. Legs black, obscure luteous at base ; prolegs ruf o- 

 luteous, brownish at base, and with a purplish spot at the tip exterioi'ly. Length, 15 

 mm. ; breadth, 3 mm. ^ 



Fourth stage. Head reddisli brown obscured by blackish, tlie suture of tlie triangle 

 dull orange, the spiuiform tubercles orange or whitish, emitting a pale hair, tlie larger 

 one in the middle of each hemisphere black ; summit spine usually black, but occa- 

 sionally in part, orange; tlie hairs all black; basal joint of antennae reddisli, tlie 

 apical black ; mouth parts reddish brown. Body marked witli black and pale yellow ; 

 a slender, pale, dorsal line extends over a part of the thoracic segments; behind tlie 

 spines, each segment of the body is black, with three narrow, transverse bands of pale 



