1893.] -»-^«^ [Packard. 



with three branches, the two terminal forming an uneven fork. There is 

 no distinct suranal plate, only a subtriangular flattened area bearing 

 along the edge six black spines of very unequal size. Around abdominal 

 segments 1-7 is a double, black band, and the lateral and subdorsal 

 spines on these segments are connected by a black band, also enclosing 

 the spiracles ; these short bands alternating with long bands passing over 

 the body. The thoracic legs are black ; the abdominal legs dull ochreous, 

 with a large, black patch covering the outside. The anal legs are rather 

 large and square, ochreous, the hinder edge pitchy red. 



It may be observed that the median dorsal spines on the eighth and 

 ninth abdominal segments are forked like those of H. io ; this and H. 

 maia being apparently earlier forms. 



Stage II. — July 10, 11. Length, 13-15 mm. The head is as wide as 

 the thoracic segments (exact width, 2 mm.) ; it is chestnut brown, a 

 little darker on the sides above the eyes and on the clypeal region. The 

 spines on the prothoracic segment are much as before, hut stouter and 

 shorter. The dorsal spines on the second and third thoracic segments 

 are much as before but not quite so deeply forked ; they are dusky amber 

 wax at the base, and black beyond ; they are irregularly spinose from 

 base to tip ; each fork bears a white hair. All the other spines are black. 

 The "caudal horn" on eighth abdominal segment is stouter at base, the 

 trunk with larger, longer and more numerous spinules, which end in a 

 bristle which is not present in Stage I ; it is still evenly forked. 



The subdorsal spines are now much shorter than before and simple and 

 conical ; while the lateral series, instead of being nearly as long as the 

 dorsal ones and deeply forked, are short and stout, ending in three short, 

 stout, piliferous spines. 



The body is now dull chestnut, with dusky discolorations, but without 

 the decided black bands and spots of Stage I, the body being decidedly 

 darker. The black spiracles are surrounded by a diffuse black ring. The 

 thoracic legs are black ; the middle abdominal legs jet-black outside, on 

 a chitinized portion ; the anal legs are of the color of beeswax, with a jet- 

 black spot or wart at the tip, and a dusky patch on the sides ; these black 

 plates are larger and longer than in Stage I. 



The descriptions of Stages III and IV were drawn up from a series 

 reared at my request bj' the late Mr. S. Lowell Elliott and preserved in 

 alcohol ; the colors are described from a set of drawings by Mr. Bridg- 

 ham. Mr. Elliott observed five stages. 



Stage III. — (Preserved the third day after the second molt.) Length, 

 30 mm. ; width of the head, 3 mm. The head is narrow, about one half 

 as wide as the second and third thoracic segments ; chestnut brown with 

 two pale, longitudinal bands in front, each band ending at the base of the 

 pale antennae. The two dorsal spines on the prothoracic segment are much 

 sliorter than in Stage II, with much stouter lateral spinules, and with 

 shorter forks at the tip, and the spines on the trunk are shorter. The 

 two second thoracic dorsal spines are a little stouter than before, but are 



PROC. AMER. PHILOS. SOC. XXXI. 141. U. PRINTED MAY 8, 1893. 



