BIRCH CATERPILLARS. 491 
states to live on Juglans ; later (Entom. Corresp., 1869, p. 300, pi. 3, fig. 8) he figures 
the larva, and adds apple to the food-plants. Walsh (Proc. Bost. Soc. Nat. Hist., 
February, 1864, v. 9, p. 298,299) first describes the imago and says, "The larva fed 
on hickory leaves, but I have met with two specimens on the button-wood or syca- 
more." Packard (Guide, Study Ins., 1869, p. 290, and Bull. 7, U. S. Entom. Comra., 
1881, p. 77) briefly describes the larva, cocoon, and imago, figuring the last. A single 
larva of this species, taken on Betula alba at Belmont, Mass., 12th August, 1882, pu- 
pated 17th September, and emerged 1st July, 1883. The excrement of the larva has 
a peculiar form, being cup-shaped, with a deep concavity and comparatively thin 
walls, which are somewhat shriveled about the margin in drying. The larva, when 
disturbed, exhales an odor difficult to describe. A short time before pupation it turns 
whitish. (Psyche, iv, p. 297.) 
18. The American Silk-worm. 
Telea polyphemus (Linn). 
I have found this caterpillar in different stages of growth at Bruns- 
wick, Me., through August, on Betula populifolia. 
19. The Unicorn Caterpillar. 
Schizura unicornis (Abbot and Smith). 
This caterpillar, which is common in orchards, has been detected on 
the birch by Mrs. Dimmock, whose notes on it are subjoined : 
Coelodasys unicornis Abb. and Smith (Nat. Hist, Lepid. Ins. Ga., 1797, v. 2, p. 165, pi. 
■86). Harris (Rept. Ins. Injur. Veg., 1841, p. 306,307) describes the larva of this spe- 
cies and gives as food-plants plum and apple, and adds to them, on authority of Ab- 
bot, Prinos verticillatus. Harris (Entom. Corresp., 1869, pi. 2, fig. 8) gives a colored 
figure of the larva. Payne (Amer. Entom., October, 1870, v. 2, p. 341) notes that the 
larva mimics partly dead and partly living margins of leaves. Lintner (Entom. 
Contrib., No. 3, 1874, p. 131) describes and figures the larva, adding Corylus americana 
and Prunus virginiana to the previously known food-plants ; his figure is copied in 
Amer. Nat., November, 1874, v. 8, p. 691, 692. Packard (Bull. 7, U. S. Entom. Comm., 
1881, p. 136) adds Crataegus to the food-plants. The larva also feeds on Betula alba. 
20. Schizura ipomece Doubleday. 
According to Mr. Koebele the caterpillar occasionally feeds on the 
birch. 
21. Schizura sp. 
Another unicorn-like larva occurred on Betula populifera, Brunswick, 
August 29. 
Larva. — Head very large, much larger (about twice) than in S. unicornis on elm; 
full, much enlarged towards the vertex, which is bilobed; a double row of light, 
almost white, spots down the front, clypeus white; side of head whitish brown, and 
the head elsewhere is marbled with whitish in a net-work of light brown lines. 
Hump (dorsal) on the first abdominal segment bilobed and much larger than in uni- 
cornis ; the two forks of the hump deep reddish. The median brown dorsal line is 
much broader than in unicornis. Side of thoracic segments not so light green as in 
