GRAPTA I. 



larva there is great variation in the color of the spines from deep red to yellow) ; 

 over the feet from 2 to 10 is a simple red spine ; on 2 is a dorsal row of six 

 simple black spines; spiracles conspicuous, black in white rings; head obovoid, 

 rather flattened, deeply cleft, the vertices high, and each bearing a stout and 

 black process, ending in a long spur, with five others about its base, each hair- 

 tipped ; the face covered with simple spines and tubercles, some minute ; on each 

 side below vertex are four long spines, black, the rest are mostly white, each 

 with hair ; color either deep red-brown or red, about the ocelli a large black 

 patch. From 4th moult to pupation, five to six days. 



Chrysalis. — Length 1 inch, greatest breadth .3 to .32 inch; cylindrical; 

 head case prolonged, compressed transversely, at each vertex a long conical 

 process; mesonotum elevated, the carina prominent, thin, nose-like, more rounded 

 on the anterior side than in Comma, followed by a deep depression ; wing cases 

 raised, flaring at base, compressed in middle, with a prominent point on the 

 margin on dorsal side ; on the abdomen three rows of tubercles, those corre- 

 sponding to the dorsal row of the larva minute, to the first laterals large and 

 conical, the pair in the middle of the series particularly prominent; those in the 

 excavation gilded ; color variable, in shades of brown from light yellow to dark, 

 often clouded with olivaceous or lilac; sometimes a dark green stripe on the side 

 of abdomen beyond wings. Duration of this stage from seven to eleven days, 

 accordinsr to the weather. 



D 



Iktekrogationis is both sexually and seasonally dimorphic. Mr. Scudder, 

 But. N. E., T, 329, has thus spoken of this peculiarity : " The two forms differ so 

 greatly and constantly from each other, not only in coloring but in the form of 

 the wings, and even in the abdominal appendages, that they have been consid- 

 ered distinct species ; in each form, too, the sexes differ considerably in the 

 coloration of the under surface of the wings, so that the species includes four 

 sets of individuals, which may be distinguished quite as readily as a great many 

 acknowledged species of the best studied faunas." Also, page 317 : " Here is an 

 insect where there are two very distinct forms in each sex, and in each of which 

 the sexes are readily distinguished by the coloration of the wings ; they dift'er in 

 the brightness and variegation of the lower surface of both wings, and the ob- 

 scurity of the upper surface of the hind pair, . . . not only differ in the mark- 

 ings of the wings, but also in their form, .and in the structure of the genitalia." 



Part 9, Volume I, which contained the two Plates of this species, appeared early 

 in 1872. I had established the fact of seasonal dimorphism the preceding summer 

 by raising larvfe of the June and July broods from eggs laid by the form Um- 

 BROSA, in both cases finding the two forms among the resulting imagos. In the 



