Studies on Life-hislory of Bornbycine Moths. 59 



Recapitulation of ajqoearance of early larval features. 



1. Appearance in sta<^e III of the pencils on the prothoracic and 

 8th abdominal segments. 



2. The four median dorsal tufts on the four basal abdominal seg- 

 ments well developed in stage III. 



8. The warts of the lateral row become bright flesh-red in stage 

 III. 



4. The two dorsal eversible glands become bright coral-red in 

 stage II. Thus, all the features of the full-grown larva, such as 

 the high colors and the white and black tufts or pencils, which 

 render it so conspicuous, appear in the 3d stage. 



The early stages of Orgyia leucostigma (Abbot and Smith). 



Larva, stage I. — (Drawn up from alcoholic specimens from Dr. 

 Ililey.) Length 3.5 mm. The head is small and not so wide as 

 the body. It is deep chitinous or amber-ochreous. The body is 

 rather long and slender, cylindrical, pale yellowish flesh color, with 

 two broad irregular, dark, more or less broken subdorsal lines, 

 which are most distinct on the abdominal segments, the space 

 between the lines being sometimes irregularly bridged over by 

 offshoots from the main lines. 



The 1st thoracic segment is slightly wider and larger than those 

 behind it, but looks larger than it really is from the pair of very 

 large lateral piliferous tubercles which cause the larva to resemble 

 that of a Clisiocampa or rather a Gastropacha. These tubercles are 

 large, prominent, and rounded, bearing about 20 spinulated hairs of 

 varying length, the longest being about two-thirds as long as the 

 body. All the hairs are brown, some being paler and taper to a 

 point. There are no clavate hairs on the body. The piliferous 

 tubercles on the 2d and 3d thoracic tubercles corresponding to the 

 lateral prothoracic ones above described are slightly smaller than 

 those on the succeeding or abdominal segments; the latter, i. e., the 

 subdorsal ones arising from the dark subdorsal lines, all being of 

 the same size. The two subdorsal lines run between two rows of 

 tubercles, the inner row being one of the two dorsal median rows ; 

 the tubercles of these two median rows are much smaller than the 

 outer rows, the latter set being a continuation of the large protho- 

 racic "lateral" ones. Now those of the two medio-dorsal rows are 

 small in front, but become larger on the Gth, 7th, and especially the 



