1914] A Study of Dryophanta Erinacei. 9 
cavities, and the result of the breeding experiments, it was 
evident that the parasites inhabited the central cavities, while 
the inquilines, though occasionally found in this region, were 
mostly confined to the lateral and peripheral cavities. 
Owing to the small percentage of several of the parasites as 
shown in Table I, we were able to breed out only five species. 
The descriptions of the larval forms obtained are as follows: 
Decatoma flava: The larval form of this Chalcid, (Fig. 34, Pl. IV), 
when mature measured 14mm. It possesses slender bidentate man- 
dibles, (Fig. 33, Pl. IV). The setz are short and spine-like, arising 
from distinct, prominent tubercles, and are located as in diagram, 
(Fig. 42, Pl. V), six on the head, ten on the prothorax, eight on the 
mesothorax, six on the metathorax, and four on each of the abdominal 
segments. 
The egg, (Fig. 32, Pl. IV), is flask-shaped and measures 200u.xd0Ou., 
neck 560u., and pedicel 56u. It is pigmented, and becomes brownish 
black on maturing. The long neck lies cephalad in the ovary of the 
adult, and the larva emerges from the egg at the base of the neck, 
(Fig. 32, Pl. IV). Thus the neck is not comparable to the long pedicel 
of the eggs of the Cynipide. The short, crooked pedicel at the opposite 
pole represents in atrophied form that found in the Cynipide. 
Eurytoma studiosa and Eurytoma auriceps: The larval forms of 
Eurytoma studiosa and Eurytoma auriceps are so similar that it is 
impossible to determine specific characters. The one shown in Fig. 43, 
Pl. V, always bred out to Eurytoma studiosa during the winter, but 
during the summer larve corresponding in all respects to the diagram 
bred out to both Eurytoma studiosa and Eurytoma auriceps. Hence 
the general characters given here may be considered generic rather than 
specific. Fig. 35, Pl. IV, gives a general view of this larva. 
The mature larva measures 14mm., having bidentate mandibles 
similar to that shown in Fig. 33, Pl. IV. The sete are long, slender, 
with distinct tubercles, and give the body a very hairy appearance. 
The general distribution of these, (Fig. 48, Pl. V), is twelve on the head, 
ten on the prothorax, ten on the mesothorax, ten on the metathorax, 
six on the first abdominal segment, four on each of the second, third, 
and fourth segments, and six on each of the remaining segments. The 
larva can be readily distinguished from the larva of Decotama flava by 
the length of the sete, those of the latter being short, spine-like, and 
fewer in number. 
The egg is flask-shaped measuring 240u.xl44u., neck 720u., and 
pedicel 64u. The neck lies eee nelae in the ovary of ae adult, and the 
embryo emerges from the egg just at the base, (Fig ig. Pl TV) ihe 
pedicel is short, curved, and aborted. The egg 1s apeaveeec! and 
becomes black on maturity. It is quite similar in form to the egg of 
Decatoma flava, but is slightly larger, and deeper in color when mature. 
The egg of Ormyrus ventricosus is flask-shaped measuring 200u.x 
120u., (Fig. 31, Pl. IV). In this Chalcid egg the pedicel is absent. 
