ANDRICUS CURVATOR. oO” 
stubs as on young andold trees. The leaf is consider- 
ably distorted by the growth of the gall, and fre- 
quently the material which would have formed a leaf 
is almost absorbed in the formation of the gall, a small 
portion only developing to form a ridge or frill upon 
the surface. Under such conditions of growth the 
gall-mass is usually more or less globular, but when 
situated upon the blade of the leaf the shape is 
very irregular, although the bulk may not be more 
than normal. 
A solitary mature globular specimen on the end of 
a twig, having little or no leaf membrane attached, 
has the appearance of a small gall of Cynips Kollavi. 
Growth is rapid, and during the early part of the 
time the gall is solid and firm, although somewhat 
succulent, and it extends in equal, or nearly equal, 
proportions on both surfaces of the leaf. As maturity 
approaches a large cavity is formed, within which is 
the inner gall; asmall, reddish-brown larval cell, ovoid 
in shape, loosely adherent, with very thin walls, and 
about 2 mm. in its long axis, occasionally with a minute 
papilla at one end. 
Two, three, and sometimes four galls will anastomose, 
and upon cutting the mass open it will be seen that 
the inner galls are in some cases separated by very 
thin septa, or the cavity remains undivided. 
When gall growth takes place at the base of a 
petiole the whole of the petiole is involved and a con- 
siderable swelling results. When situated at the: 
extremity of a twig, and small portions of leaves 
develop upon the gall structure, there is a close 
resemblance to a gall of A. inflator. 
It is extremely abundant on some trees, affecting 
mostly the small twigs springing from the trunk, where 
not infrequently almost every leaf is galled. It may 
also be found in great plenty on bushes and very young 
trees. Apparently it occurs but rarely on the higher 
boughs of old trees. 
Some of the imagines of Aphilothrix collaris emerge 
