32 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



tubercles on the front edj^e of the .shield, of which the four dorsal ones — two on each side — are a 

 little larger than those on the sides below. 



The false horns of the second and third are now large and high, erect, like a dog's ears, iind 

 roughly tuberculated; they are of nearly the same size, but those on the third segment are 

 slightly smaller than the anterior pair. They are not in this stage one-half as long as the 

 segment bearing them, and end in a line short seta, l)ut the "horns'' do not end in a single 

 point, as the accompanying two or three terminal tuberculets project up nearly as far as the most 

 distal one. The two little double-headed tubercles (i and ii,), one pair behind each false horn, 

 are minute, like those behind on the abdominal segments, but still somewhat larger. On the 

 al)dominal segments (1-7) each of the eight transverse annulets or folds is raised dorsally into a 

 setiferous conical secondary tubercle. The caudal horn is as long as the seventh, eiglith, and 

 ninth segments with the suranal plate, all taken collectively, ^ and is densely covered with tine 

 setiferous simple tubercles. The tubercles on the median line of the abdominal segments 1 to 7 

 now form a white line, as in the fully grown larva. 



The two lateral dorsal lines on the two hinder thoracic segments are now indistinct, but the 

 ol)lique greenish white lines are more distinct. The legs are as in stage I. 



stage III. — Described August 21. Length, 15-25 mm. ; head, 2f mm. in width; length of caudal 

 horn, 3 mm. Now the false horns are higher, and the white median dorsal and seven long lateral 

 oblicjue lines are whiter and more distinct. The slight yellowish green ground color of the 

 previous stages has disappeared and the line is uniformly pale green. The head is still wider than 

 the body and rough with projecting white, sharp conical tubercles. The four false horns are 

 now larger than before in proportion to the size of the body, and covered with minute white 

 conical sharp tubercles; they are about one-third as long as the body is thick; those on the third 

 thoracic segment a little smaller than those on the segment in front. The white medio-dorsal 

 line of tine tubercles on the abdominal segments makes a distinct rough serrated line. The seven 

 pairs of oblique white lines are made up of sharp irregular white conical tubercles, each with 

 from one to three points, while the eight transverse ridges are covered with similar tubercles, 

 making a white crest on the edge of each ridge. The spiracles are still pale and inconspicuous 

 in my examples, but in those drawn by Mi-. Joutel they are represented as black. The caudal 

 horn has now a yellowish tint. 



Stage IV. — Length, 18 mm. One molted August 2i». It is the same as in the previous stage, 

 but the tubercles are whiter and the lines more marked. The spiracles are now black. It molted 

 again September 8. 



Stage Vand last. — Length, 45-65 mm. Head, a little more than one-half as wide as the body, 

 reddish olive-green, witli two faint, paler lines converging on the vertex from each antenna. The 

 surface of the head with tine dark tubercles. The four false horns are about one-third as long as 

 the body is thick. The two on the second thoracic segment are a little more pointed and slenderer 

 than the two behind, but the four are now of the same length. A dorsal line of small tul)ercles 

 connects each of the false horns on a side (indicated in stage II), and the two lines meet on the front 

 edge of the second abdominal segment. The ciiudal horn is of the same color as the thoracic 

 ones, pale at the end; it is soft and flexible, not stifl' and rigid. The groimd color of the body 

 is now, in my examples, of a uniform reddish olive, though hardly green. Mr. Joutel's drawing 

 represents the larva as pale whitish green, and 1 suspect that there is in this species a slight 

 degree of dichrouiatism. The spiracles are black on each side of the slit or opening. The 

 thoracic legs are now bright red. The suranal plate is convex, with a few fine dark tubercles; 

 it is reddish on the edges. The posterior three-quarters of the anal legs are also reddish-olive. 

 The mid-abdominal legs are olive, of the same hue as the body. The larva began to pupate at 

 Brunswick, Me., September 18. The color of the body when about to transform is of a peculiar 

 rust-red purplish tint." 



"In a specimen found in Providence, September 24, the ground color is of a peculiar glaucous green, with a 

 pearly tinge; the lines and bands all white, as also the granulations. The tips of the thoracic and of the caudal horns 

 are dark. It is to be observed that this larva, which lives on the elm, is of the same hue as Nerke hklentala, while 

 the horns are, like the tubercles of the Nerice, tipped with dark. Does this not suggest that the color of the elm 

 leaves, with their dark tipped serrations, have reacted alike on thelarv.'e of the two moths? 



