1929] 
Four New Forms of Eriophyes 
305 
pubescens, urticifolia, and verrucosa as hosts of this sub- 
species ; it has also been considered as the cause of the bud 
deformations of B. lutea. However, the mite found in the 
deformed bud masses of this latter host differs distinctly 
from either the typical species or the subspecies described 
by Nalepa. It has a larger body size, more striae, and a pair 
of accessory setae setting it off from the typical species. 
From the subspecies mentioned it differs in the possession 
of the accessory setae, larger body size, and shortened shield. 
The gall produced by dissimilis is quite different from that 
of the other two forms mentioned and appears to be limited 
to the single host from all reports and collections, as well as 
not being associated with a witch’s broom formation. The 
early descriptions of the gall were made without any 
attempt to give the species of mite causing it. In 1909 Steb- 
bins described the gall again from the same host and attri- 
buted it to a new species of mite, Eriophyes betulse, without 
examining the mite and giving a description of it. Unfor- 
tunately, the name thus chosen had already been used by 
Nalepa to designate the species of mite producing the pouch 
gall on Betula verrucosa in middle Europe and southern 
Tyrol. Figure 2 represents the morphological characters of 
the mite whose description follows. 
The body is cylindrical, tapering gently from the thoracic 
shield to the telson ; the female measures about 240 microns 
in length and about 55 microns in width. The thoracic shield 
is semi-elliptical, clearly delimited posteriorly and rounded 
off anteriorly; the center field has three full length wavy 
ridges traversing it, the two outer ones diverge toward the 
posterior border of the shield; on the side there is usually 
an indistinct ridge from the region of the anterior border 
curving back about the setal tubercles near the posterior 
border. The dorsal setae are coarse and about 20 microns 
in length. The rostrum is short, stout, and ventrally curved. 
The legs are relatively short ; the tarsus and tibia are equally 
long (c. 5 microns) ; the claw bristle (c. 10 microns) is 
curved and slightly overreaches the feathered claw of the 
second pair of legs and equals that of the first pair; the 
feathered claw is large and four-rayed; the outer setae are 
