1890 .] 
541 
[Packard. 
S. ipomece, but are decidedly shorter. The dorsal and other tubercles 
are just as in S. ipomece. It is probable that other specific dis- 
tinctions are to be sought for in this style of coloration. Indeed, 
as may be seen in alcoholic specimens, the head of S. leptinoides is 
simply rough on the surface and uniformly resinous, while in S. 
ipomece of this stage the surface in front and on the sides are di- 
vided into whitish areas bounded by brown lines. The coloration 
in general is much alike in the two species. The dorsal band along 
the thoracic segments and the Y-shaped whitish-yellow mark on 
the sixth and seventh segments are nearly as in the third stage of 
S. ipomece. 
SUMMARY OF THE STEPS IN THE ASSUMPTION OF THE GENERIC OR 
ADAPTIVE, i. e., PROTECTIVE CHARACTERS, OF THREE SPECIES OF 
SCHIZURA. 
The supergeneric features of the partly elevated, uplifted anal 
legs, and the difference in the size of the tubercles appears at the 
time of hatching. 
1. The head becomes marked much as in the adult in the second 
stage. 
2. The tubercles begin to be differentiated in the second stage, 
when the prothoracic tubercles are much smaller than in the first. 
3. The dorsal tubercles of the first abdominal segment, origi- 
nally separate, become united at the base in the third, and form a 
single high-forked tubercle in the fourth stage. 
4. The glandular hairs differ generically in the second stage from 
those in the first. The flattened glandular hairs are present in the 
first and second, and disappear in the fourth stage. 
5. The V-shaped dorsal mark on the sixth and seventh abdomi- 
nal segments appears at the end of the third stage and is due to the 
coalescence of three separate, whitish-yellow spots. 
6. The pea-green color of the meso- and metathoracic segments 
appears at the end of the third stage. 
It thus appears that the mimetic colorational features, being 
those which especially enable the larva to escape observation, ap- 
pear shortly before the creature is half-grown, these changes occur- 
ring at the end of the third stage, while the movable terrifying tu- 
bercle of the first abdominal segment becomes developed at the 
same time. 
When feeding on the edge of a leaf, the Schizurse exactly imi- 
