564 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



Larva before last molt. — Head large oval, flattened iu front, narrowing towards the 

 vertex, wliich is slightly bilobed ; the head is wider than the thoracic segments ; the 

 body is thickest on the second and third abdominal segments, on each of which is a 

 thick fleshy conical soft tubercle, the apex falling over backwards ; they may be 

 elevated and somewhat enlarged or depressed, the anterior tubercle the larger of the 

 two; the body is much humped dorsally on the eighth segment ; supra-anal plate 

 smooth, much rounded ; the anal legs slender, not nearly so thick as the other 

 abdominal legs. General color pearly glaucous whitish gray, somewhat marbled 

 with brown ; head of the same color, marbled with brown; a broad faint lateral baud 

 shaded behind with white. A brown dorsal line extends from behind the head to 

 apex of second tubercle on third abdominal segment; thence a faint vascular line 

 extends to end of supra-anal plate. The hump on eighth segment pale rust yellow- 

 ish-red on sides, deeper above in the middle. A pale pinkish stigmatal line. 

 Length, 20"im. 



Mature larva. — Does not differ except in size from previous stage. Under side of 

 body dusky ; the pale lilac lateral line sends a branch down the nuddle of the feet 

 on the sixth abdominal segment. Length, 40'"'". For description of the moth see 

 p. 456. 



15. Sehizura ttnicornis (Abbot and Smith). 



This species is common both on the willow and thorn late in August 

 in Maine. August 28 one had spun a slight cocoon, but up to Septem- 

 ber 4 had not pupated. 



The dorsal hump is not so soft and retractile or sensitive as in the 

 larva of the following species : 



Larva. — Has a shorter smaller dorsal retractile than in Ccelodasys. Thoracic seg- 

 ments pea-green ; the dorsal -shaped mark on the seventh segment is prolonged to 

 the front edge of the sixth segment, this part really forming a separate narrow V, in 

 front of the apex, of which on each fourth and fifth segments is a dusky brown patchy 

 between the reddish-brown piliferous warts. Length, 25""". 



Before the last molt the larva is the same as matui-e form. Length, 15 to 18""". 



16. Sehizura larva. 

 (PI. V, fig. 3.) 



Several caterpillars of this species were found on the willow at Bruns- 

 wick, August 25, by Mr. H. H. Wilder. This caterpillar has a retractile 

 horn (much more slender and retractile than iu the one on thorn bush) 

 on the first abdominal segment, which may be partially telescoped in- 

 wards or invaginated, forming Ihree false joints, and the fork at the 

 end is composed of two movable piliferous slender tubercles which 

 slightly diverge more or less. 



Larva. — Head very large, high, narrowing and bilobed above; on first abdomina] 

 segment an unusually high horn or soft tubercle, forked at the end, the horn 

 itself being extensible; on the eighth abdominal segment a high double conical tu- 

 bercle; anal legs slender, as usual in the genus ; abdominal segments 2 to 7 with two 

 dorsal piliferous warts, those on fourth and fifth segments much larger than the 

 others. Body rust-red, pale green on the side of the three thoracic segments and 

 edged above with white; on the back, between the first and third, there is a broad 

 diffuse whitish lilac band; a distinct large V-shaped yellowish-white mark on the 

 seventh abdominal segment; and two concolorous dots below the seventh pair of 

 abdominal spiracles. Length, 20™™. 



