29 
Mr. W. Saunders has reared the moth from a caterpillar found on the 
Beech, and it will probably occur on other trees. 
Larva . — Head rather small, much narrower than the body, somewhat flattened in 
front. First thoracic considerably narrower than the second thoracic segment ; sec- 
ond and third thoracic segments with lateral slight swellings ; the black spiracles are 
situated on dusky swellings ; on the fifth abdominal segment is a dusky dorsal hump, 
edged in front with white, consisting of two rounded conical tubercles. Supra-anal 
plate rounded with two stiff terminal setae ; anal legs rather broad, with a setiferous 
fleshy conical tubercle on the upper edge. General color of head and body lilac-brown ; 
head slightly more reddish, and on the back of each segment is a pair of whitish spots, 
especially distinct on the second thoracic, but wanting on the first segment. Supra- 
anal plate and anal legs sea-green, mottled with dusky spots. Length 28 mm . 
Pupa . — Body rather thick ; mahogany-brown, ends of wings and legs reaching to 
the posterior edge of the third abdominal segment. Terminal spine of the abdomen 
(cremaster) large, flattened beneath, broad, triangular ; the upper and undersurface 
with fine irregular wavy longitudinal ridges. Four lateral curved bristles and a ter- 
minal pair about twice as thick and long as the others. On the under side at the base 
of the spine are two orbicular areas like flattened tubercles. Length 12 mm . 
Moth .— Fore wings pale whitish, with fine cross specks as usual ; the basal cross 
line is heavy on the costa and bent sharply outwards on the subcostal, with a smaller 
angle on the median vein and a larger angle on the submedian vein. The great but 
obtuse angle made by the outer line extends quite near the outer edge of the wing. 
Half way between the apex and the outer line two brown costal patches ; two un- 
equal black patches near the internal angle. Beneath, the lines and cross specks are 
reddish-brown. Expanse of wings 33 mm . The specimen does not agree with either 
of the four figures in my Monograph of Geometrid Moths, differing especially in the 
shape and direction of the outer line. 
THE CLEFT-HEADED SPAN-WORM. 
(Ampliydasis cognataria Guen.) 
This common inch or measuring worm is the largest species we have 
met with feeding on the Willow, and may be readily recognized by its 
deeply cleft head and reddish-brown or green body like a reddish or 
green willow twig, which it closely mimics. We have noticed it as 
frequently in Jackson, N. H., as in Maine. It becomes fully fed by the 
first week in September, my specimens transforming September 8, the 
chrysalis entering the earth. The moth appears in June in Maine, late 
in May in Southern New England and New York. I have raised this 
moth in Maine from the Larch (pupating September 15), also from the 
Missouri Currant, an ornamental shrub; also from the Apple, Elm, 
Cherry, and the Aspen in Rhode Island, though the Willow is probably 
its native food plant, as it occurs in greatest abundance on that tree. 
Mr. Lintner states that the larva feeds on the Maple; that the caterpillar 
entered the ground for pupation August 11, the moth emerging the 
latter part of May. (Ent. Contr. Ill, 166.) My specimens emerged in 
Providence, May 13. The larva found on the Aspen is greenish and 
like a fresh aspen twig, with whitish granulations, which are black on 
the tubercles. 
