Packard.] 
556 
[Feb. 19, 
Second stage. — Length of body 11 ; of stemapods 8 mm. It dif- 
fers from the foregoing species of the same stage in wanting the 
frontal tubercles of the head, which is paler, and in the longer and 
slenderer protlioracic horns, the latter having smaller spines ; it is 
also } 7 ellow beneath. The spines on the stemapods are finer. There 
is more yellow on the sides of the body, the yellow extending along 
the sides of the stemapods. 
Third stage . — Length of body 15 ; of stemapods, 4 mm. It dif- 
fers from the third stage of Cerura borealis in the longer cervical 
shield and the- shorter horns, so that the shield is more normal in 
shape, being as usual in many caterpillars. The piliferous warts 
over the body are a little larger, while the dorsal reddish saddle- 
like spots are more definitely liAed with deep red. 
LIFE-HISTORY OF CERURA CINEREA WALK. 
Although Messrs. H. Edwards and S. L. Elliot (Papilio, hi, 130) 
have well described the larva of this species, which lives on the 
willow, I have been able to compare some very well preserved al- 
coholic specimens of the mature and young caterpillars (kindly 
loaned by Professor Piley) with similar stages of the two forego- 
ing species. 
Second stage.- — Length without the filamental legs, 12 mm.; of 
the latter, 7 mm. It is at once distinguished from the larvae of 
C. occidentalis and C. borealis of the same size by the larger bristles, 
the warts bearing them being scarcely larger, but the bristles them- 
selves being two or three times as large. The head is as usual in 
the genus, as are the two lateral prothoracic “horns,” and the cer- 
vical shield from which they arise. The “horns” are as in C. occi- 
dentalism being spined in the same manner, and pale yellowish be- 
neath. A large reddish triangular dorsal patch extends backwards 
from the horns, the apex resting on the second thoracic segment. 
The back is discolored from the third thoracic segment to the end 
of the supra-anal plate, not so decidedly reddish as in my specimens 
of the two other species previously described. 
Mature larva.-— -Length, without the “ tails,” 38 mm. ; of the fil- 
amental legs, 15 mm. The head is small, being one-half as wide 
as the body, reddish, but darker on the sides. 
The prothoracic horns in this stage are reduced to smooth pro- 
jecting tubercles of the usual size which are blackish -above and 
pale below. Body pale green. From the horns a lilac-red, nearly 
equilaterally triangular spot edged with yellow, extends backwards 
