74 THE CANADIAN ENTOMOLOGIST. 



but not so wide as the head; the front edo;e is somewhat raised, /. e., flares 

 up, and bears a remarkably complex armature. The two dorsal tubercles 

 are broad, thin (in a fore-and-aft sense), and divided into seven heads or 

 subtubercles, one or two of which are smaller and shorter than the others, 

 each digitiform tuberculet bearing a long spinulate black seta; the setreare 

 of nearly equal length, and nearly as long as the entire main or master 

 tubercle. As compared with those of Eacles imperia/is, Stage I., these 

 tubercles are much thinner, and are 7-headed instead of being 2-headed, 

 /. e., simply forked. 



Below on the front edge of each side is a smaller tubercle of the sub- 

 dorsal series about one-third as long and large as those of the dorsal pair, 

 ending in three subtubercles, each of which bears a black spinulated seta. 

 Just below the spiracle is a small, simple, infraspiracular tubercle, and 

 below this a low minute 3-headed one. Behind this series of four tuber- 

 cles (on each side) is a dusky, narrow, chitinous band or rudimentary pro- 

 thoracic plate or shield, which passes down each side of the segment, not 

 quite reaching a point opposite the spiracle, /. e., not as far down as the 

 spiracle. 



On the 2nd thoracic segment are two dorsal tubercles (/), which are 

 small, digitiform, 2-headed, the heads diverging. These are smaller than 

 the corresponding pair on the rst abdominal segment, but larger than those 

 of the hinder pair (//) on the same abdominal segment. 



On the 3rd thoracic segment is a pair of enormous horns, which are 

 slightly more than half as long as the body. They are not stiff, and easily 

 bend over, but with a thin integument, the surface of which is crowded with 

 short, erect spinules, some of which are conical, others blunt. These two 

 appendages are nearly as thick as the segment is long, their greatest 

 diameter being a little above the base ; they are forked at the end, each 

 fork being about twice as long as thick, and much rounded at the end, and 

 giving rise to a stout spinulated seta, which is of moderate length, /. e., 

 about twice as long as the greatest diameter of the horn itself The horns 

 of this pair are much larger than those of Aglia tan of the same stage, and 

 differ in the trunk, and two branches of the fork being much thicker, while 

 the short spinules do not give rise to a hair. It is most probable that 

 the caterpillar moves these horns with more or less freedom, and that they 

 are deterrent structures. 



On the back of abdominal segments 1-7 are two pairs of dorsal tuber- 

 cles, those of the anterior pair (/) digitiform, as long as the horns are thick; 



