185 
lml were abundant on the poison ivy at Normal, Illinois, in June 
ool. A single mite was observed. ’ 
; 
Phytoptus acericola, n. sp. 
lang dUCeS gallS ° n the leaVeS ° f the SUgar ma P le > Acer saccharinum, 
In five examples of this mite the striae were counted, and in three 
f them numbered 30 and m the other two, 28 and 29, respectively 
5 e prongs of the teather'like appendage seem to be three. The 
ength is about .00/5 inch. This form was found in June both 
mong knobbed hairs and in galls on the sugar maple, but there 
ppeared to be only one species represented. 
The gall is very slender, tapers to both extremities, and bears a 
^rong resemblance m general form to the nail galls described by 
. 1 V ; u - y f 1 rom the leav( ?s Of Ampelopsis. The walls are 
.iiiformly thin, and present no internal roughness. The height is 
lout .±9 inch, and the diameter .045 inch. Phytopti were abund- 
pt m these galls collected at Bloomington, Illinois, June 22, 1881, 
Phytoptus quadripes, Shimer. 
I Produces galls on the leaves of the soft maple, Acer dasycarpum, 
This is the Phytoptus upon which Dr. Henry Shimer founded his 
C 87 To 49 tv 18 ? C T Se y . sln f te species, the stri® numbering 
tbit 7 ,*? 42 i 1 16 ^ ng - h IS aboi ! t - 008 mch - Th e tarsal claw is 
ghtly curved and ends m an evident knob. The feather-like ap- 
ndage lias lour parrs of prongs. The color varies from pale yel- 
vish to light orange. Sexually mature females, the young and 
f .gs occur m the galls in June. 
The galls appear with the unfolding of the leaves in spring as 
-ght swellings of the parenchyma, and as the leaf reaches its per- 
Slze . the y expand usually into top-shaped galls, arising from the 
per side of the leaf. The form varies to some extent, some of 
L f a lS b ? 1 mg u dl800ld or more or less spherical, while occasion- 
y two galls have a common neck and opening. At. first the 
'or of the galls is like that of the unfolding leaf, dull purple or 
pen;, later it assumes the light green color of the veins and 
; n et ? ’ ,, an< t stl h later changes, in many cases, to purplish 
I wards the end of summer it. dries up and becomes black. 1 The 
f*' er surface is smooth, but the walls are broadly and irregularly 
pressed, making a very uneven outline. On the under side of the 
r h the P 0 sitl0u o* the galls is usually indicated by an impression 
.h a tuft of white hairs in the center, which tuft covers the 
juiing into the gall. Occasionally the opening and tuft are borne 
m a slight elevation. The height of one of the largest galls 
isured from the upper side of the leaf, was .1 inch; the diam- 
was . 1,1 inch. T lie galls are attached at the sides of the veins 
i‘. are s ? numerous on some leaves as to cover the entire upper 
i tace. 1 have seen trees on which there were very few ungalled 
