94 
DESCRIPTION.* 
Having a large series of this perplexing species, which is 
quite evidently the same as that described by Dr. Thomas in 
the Eighth Report of this office (p. 168) as a Tychea, and again 
by Mr. 0. W. Oestlund, in his “List of the Aphididae of Minne¬ 
sota” (p. 56) as Tychea radicola, a full description is here sub¬ 
mitted, from which it may be seen that an imperfect knowledge 
of the species has caused conflicting statements. The number of 
antennal joints, as well as other characters, throw it out of 
Tychea, and place it in Tram a, as defined by Koch. 
Wingless Viviparous Female .—Body broad-ovate, very convex, 
abdomen often subglobose, surface smooth, dirty whitish, a few 
sparse hairs on antennae and legs. 
Head rounded on front and sides, base broad, about twice the 
length, an oblong dusky spot extending from the base of the 
beak over the vertex, between the antennae, nearly to the posterior 
margin of the head, wider behind, divided by a whitish median 
line. Fully developed antennae with six distinct joints, dusky 
whitish, darker apically, the spur or sometimes the entire apical 
half of VI dark brown or blackish, tip reaching posterior mar¬ 
gin of mesothorax. Joint I very short, transverse; II nearly as 
thick as 1 at apex, but narrowed strongly towards base, about 
one half longer than I; III still longer, but not as long as I and 
II combined, about twice as long as thick; IV as long as II; Y as 
long as III, or a little shorter, wider apically; VI broad fusi¬ 
form when seen from above, thickest near middle, tapering to 
base and to apex of spur; basal part of VI as long as V, spur 
about one fourth of total length of joint. Even in some good-sized 
examples the suture between joints III and IV is imperfect, and 
these two joints are shorter, especially IY, which becomes dis¬ 
tinctly shorter than II. In other specimens of the same lot, for 
example one 1.8 mm. long. Ill and IY are much shortened and 
completely united into one joint, which is very little longer than 
YI. Y is also shorter, being about as long as II. Sensoria 
moderate in size, round, one, as usual, at apex of Y and one at 
base of spur on YI, with one or two very indistinct minute sen¬ 
soria adjoining it on the posterior side. Eyes small, ocular 
tubercle feebly elevated, with three lenses as usual. 
Thorax and abdomen unicolorous, prothorax separated from 
mesothorax by a lateral constriction, in front of which the side 
margin is subangulate. The dorsum is provided with numerous 
glands for the secretion of a waxy substance, which rises in 
short columnar tufts from each gland, giying an appearance of 
rows of tubercles. Alcohol soon dissolves most of the excretion, 
and even obliteraJes all traces of many of the glands. These 
glands are arranged in regular series, appearing in fresh speci¬ 
mens in alcohol as clear smooth spots encircled by a fine dark line. 
There are six longitudinal rows, each with one gland on each 
* By C. A. H irt. 
