136 
leaves, and most of them had curled up and were of a greenish- 
yellow hue. 3810 galls were counted on one leaf. Dr. Shimer says 
thousands occur on some leaves. 
Phytoptus, sp. 
Gives rise to growths of hairs on the leaves of the box sae 
Negundo aceroides, Moench. 
Few specimens of this Phytoptus have been seen, though the 
growths have been carefully searched for them. One of those ex- 
amined had 45 transverse striz, and was .005 inch long. 
The galls or cecidii consist of mats of tangled white hairs on the 
under side of the leaves, situated in slight concavities; on the 
upper side of the leaves the cecidii are seen as correspondingly 
slight convexities of the surface. The younger leaves and those of 
shoots at the base of trees are sometimes almost entirely converted 
into cecidii, the peculiar hairs appearing even on the upper side of 
the leaves. Such leaves never expand, but curl up and seem, from 
the abundance of the hairs, to be clothed with a fine mealy sub- 
stance. These growths are similar to cecidi of certain oaks. 
The growths are very abundant on box elders planted for shade 
on the streets of Normal, Ill., and have been seen on young trees 
in the nurseries of the neighborhood. 
Phytoptus fraxini, n. sp. 
Produces galls on the leaves of the green ash, Fraxinus viridis, 
Michx. 
This is a very finely striate species, the strie numbering from 78 
to 81. In one example 70 striz were counted, but as in others the 
number was so uniformly above 70, a mistake may have been made 
in counting. The feather-like appendage has two pairs of widely 
divergent prongs. An example mounted in glycerine measures 
.048 mm. in length. Eggs and young occur in June. 
The light-green color of these galls so strongly contrasts with the 
dark leaves that the latter appear at a little distance to be spotted 
with light. It is a depressed wart-like gall. The center of its 
cavity is about in the plane of the leaf, as the projection above and 
below is nearly equal. The outer surface is variously indented, in 
some cases as if with the finger nail. The outline seen from above 
is elongate, circular, or quite irregular. The opening beneath is a 
slit, surrounded by a raised lip clothed with white hairs. One or 
more folds with many-celled hairs at their free edges project into 
the interior, dividing it into more or less perfect compartments. 
The median of these folds is usually largest, and sometimes reaches 
the bottom of the cavity just over the opening. Side folds may be 
formed from the primary ones. The largest gall measured was .13 
inch in diameter and .13 inch in height, measuring the projection 
on both sides of the leaf. Dr. F. A. W. Thomas describes a. still 
more peculiar gall from a European Fraxinus. This gall was 
abundant in Central Illinois during the summer of 1880 and 1881. 
