281 
terous Jarva* being known to possess more than five pairs of abdomi- 
nal legs, when rearing the larva described above we again for the 
third time carefully and repeatedly observed the caterpillars when 
alive and watched the movements of the abdominal legs during 
locomotion, and saw how the two rudimentary pairs, viz., those on 
the second and seventh abdominal segments, were raised and put 
down. With the triplet in hand, and allowing the larve to walk on 
the edge of the tin box in which they had been confined, it was 
easy to see that the above-mentioned proplegs were actively used, 
performing the same general acts of extension and retraction of the 
planta as the others, and like them serving to support the body. 
The first pair, particularly, viz., those on the second abdominal 
segment, were observed to be nearly as large and long as the normal 
legs, and to be retracted and then extended, and applied to the 
surface of the object on which the body was situated, in the same 
manner as the pair directly behind which have crotchets ; and the 
same was observed as regards the pair on the seventh segment. 
(Fig. 7. a, dorsal, 4, lateral view of the larva of Lagoa crispata, 
Stage V; ¢, ventral view of the same to show the seven pairs of 
abdominal legs; @, front part of the same, still more enlarged to 
show the differences between the first and second pair of abdominal 
legs, also the under side of the head partly concealed by the pro- 
thoracic hood ; and the three pairs of thoracic legs; ¢, a side view 
of the hood, completely concealing the head; f,a tubercle with the 
hairs and spines ; g, a normal abdominal leg with the crotchets ; 9’, 
one of the legs on second abdominal segment, without the crotchets ; 
h, side view of two abdominal segments showing the spiracle and 
the lateral glandular process (4%.) behind it. Bridgham de/.) 
To further prove to others, who might doubt whether these 
mobile and extensile processes were really legs at all, I made care- 
ful camera sketches of the alccholic specimens of the freshly hatched 
larva (Fig. 1), and of one after the first molt (Fig. 5). In Fig. 7¢, 
the first abdominal segment is seen to be completely apodous, but 
the legs on segments 2 and 7 are seen to have a well-developed 
extensile planta, though without crotchets, but bearing on the out- 
side a pair of clavate sete just like those on the other legs. In 
Stage II (Fig. 5) are seen the same structures; f/., the planta ; 
* Exception, however, should be made of the larva of Phyllocnistis, and of Nepticula, 
which possess nine pairs of abdominal legs, which however bear no hooks. 
PROC. AMER. PHILOS. SOC. XXXII. 143. 27. PRINTED FEB. 7, 1894. 
