Packard.] lo4: [Mnrch 17, 



each side of the median line along the hack are faint, threadlike, fine, 

 sliort broken lines, only perceptible under a lens. Besides tlie continu- 

 ous pale-blue dorsal line, the distinctive marks are the two darker blue 

 spots, short and straight ; the one in front longitudinal and at, right 

 angles to the other, which is transverse and more distinct because situated 

 on a black field. The sides of the body are filled in with blue, containing 

 some fine ochreous lines, especially on the upper edge of the blue area 

 below the longitudinal blue mark. The ordinary spinulated hairs of G. 

 amcricnna are represented by Fig. 21. 



A variety of the larva of Vlisiocampa americana observed at Providence, 

 June 5 and 6. — One full-grown larva has the white dorsal line twice as 

 wide as usual, and broken up into a series of exclamation marks. The 

 line is interrupted at the sutures and each stripe swells out at the posterior 

 end into a knob, and on the sixth abdominal segment it is short, and suc- 

 ceeded by a large, round, while spot, while on the first abdominal segment 

 the stripe is represented by two large round spots. 



The Young Larva of Gastkopacha americana. 



Found on an apple tree at Brunswick, Me., July 28. 



Stage III {t). — Length, 17 mm. The head is rather small, about three- 

 fourths as wide as the body, rounded but flattened in front, blue slate- 

 gray, nearly concolorous with the body. The prothoracic segment is 

 much broader than the head, with a very large and prominent pale clay- 

 yellow or luteous lateral tubercle on each side, bearing numerous long 

 gray hairs. The second and third thoracic segments each with two dark, 

 flattened, button-like warts centred with grayish. The sutures at hinder 

 edge of second and third thoracic segments respectively are stained with 

 pale ochre-yellow or luteous, forming a transverse stripe which is partly 

 visible when the worm is at rest, but revealed more distinctly when it is 

 in motion. On each segment behind first thoracic are four dorsal pilifer- 

 ous warts, two most conspicuous on second and third, and others on the 

 side ; those on the abdominal segments four in number and arranged in a 

 square. From the first yellowish transverse dorsal streak is a longitudinal 

 subdorsal concolorous (yellowish) line, and below it a concolorous fine 

 hair-line between two dark lines. The body is dull, livid, bluish slate- 

 gray, mottled and finely spotted with blackish points and i)iliferous w^arts. 

 Along the side of the body the lateral tubercle, one on each side of sec- 

 ond and third thoracic segments, is large, but not so long and slender as 

 that on the segment in front, but yet they are unusually large and well 

 developed, and they are replaced on the abdominal segments by the large 

 fleshy lappets, bearing long, dense, fine, gray hairs, which are directed 

 downwards. There are as yet no traces of the dorsal tult of flattened 

 hairs present in the mature larva. On the eighth abdominal segment is a 

 decided rounded hump bearing two black flattened warts, from which 

 arise numerous fine black hairs. The dorsal hairs are in general black, 



