THE OAK GALL-MITE. 213 
but the two lateral rows are continued by smaller tubercles until near tbe base of 
the labruni. Rostrum reaching the second coxae. Nectaries yellow, about as long 
as the tarsi, slightly enlarged at base, the mouth conspicuously flaring. Style not 
perceptible. 
Winged individuals. — Antennae very slightly pilose ; fourth joint subequal to the 
fifth and two-thirds as long as the third joint ; sixth about half as long as the pre- 
ceding, and very little longer than the seventh wings, with the stigma and veins 
much as in Ch. populicola, the veins lying in narrow dusky bands. Length of apter- 
ous individuals 1.52-2.02 mm . ; length of wing 2.54 mm . 
On the under side of the leaf near the midrib. Quercus prinus May to June, 
Peoria, 111. 
Of this interesting species I have seen a number of apterous indi- 
viduals, but only a single winged specimen, which was mounted on a 
slide, kindly communicated by Miss E. A. Smith, of Peoria, 111. The 
dorsum of the winged individual is probably not tubercular, but this 
cau not be decided with certainty on account of the manner in which 
the specimen is mounted. 
Though the antennae of this species are not sufficiently pilose to jus- 
tify its being placed in Chaitopliorus, its general appearance seems to 
point to this as its rightful position. (Thomas). 
302. Chaitophorus spinosus Oestlund. 
Mr. Oestlund has found this aphid on the under side of the leaves of 
the oak, confining itself to the higher parts of the tree. 
Wingless oviparous female. — Head subquadrate in outline, straight in front, pale red 
or orange colored, with blackish spines in front and above like those on the abdo- 
men. Antennae very remote at base, about one half the length of the body ; joints 
1 and 2 as usual, 3 longest, 4 a little shorter, 5 a little shorter than 4, 6 hardly one- 
half of 5, 7 not longer than 6 or shorter, basal joints pale, apical black, with long 
white hairs as usual in this genus. Eyes large and round, with a distinct tubercle ; 
the facets are reddish-brown, the space between them whitish, giving the eye the 
appearance of a ripe raspberry just picked with the bloom still on ; no ocelli in this 
form. Beak not more than reaching second coxae, stout and hairy, pale except at tip ; 
second joint widest. Abdomen widest in the middle, tapering into a very long ovi_ 
positor behind, strongly convex above. Color pale yellow ; last segments sometimes 
reddish as the head ; above with grass-green markings, generally in the shape of a 
ring, leaving a large irregular white-like patch in the middle of the same color as 
theabdomen. Honey-tubes short and thick. Style short and thick. Length2 to 3 mn \ 
(Oestlund's Synopsis of the Aphididae of Minnesota). 
303. Burr-oak gall mite. 
Phytoptus querci Garman. 
Class Arachnida ; order Acarina. 
Produces galls on the leaves of the burr-oak, Quercus macrocarpa 
Michx. 
The mite is long and slender, and in a specimen seen among washings from a ceci- 
dium, there appeared to be an abrupt descent in the outline of the back from the 
abdomen to the cephalothorax. Length .005 inch. 
