83 
of this office (p. 168) as a Tychea, and again by Mr. O. W. Oestlund, 
in his “List of the Aphididx of Minnesota” (p. 56) as Tychea radicola, 
a full description is here submitted, 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 T'ychea, and place it in Trama, as defined by Koch. 
Wingless Viviparous Female——Body broad-ovate, very convex, ab- 
domen often subglobose, surface smooth, dirty whitish, a few sparse 
2 hairs on antenne and legs. 
a 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 ver- 
J tex, between the antenne, nearly to the posterior margin of the head, 
wider behind, divided by a whitish median line. Fully developed an- 
tenn with six distinct joints, dusky whitish, darker apically, the spur 
4 or sometimes the entire apical half of VI dame brown or blackish, tip 
“ reaching posterior margin of mesothorax. Joint I very short, trans- 
verse; II nearly as thick as I at apex, but narrowed strongly towards 
‘B base, about one half longer than I; IIL still longer, but not as long as 
; I and II combined, about twice as ‘long as thick; IV as long as Il; V 
as long as III, or a little shorter, wider “apically : VI broad fusiform 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 IIT and IV is imperfect, and these two joints are shorter, espe- 
cially IV, which becomes distinctly shorter than IT. In other specimens 
of the same lot, for example one 1.8 mm. long, IIT and IV are much 
shortened and completely united into one joint, which is very little longer 
than VI. V is also shorter, being about as long as IJ. Sensoria mod- 
erate in size, round, one, as usual, at apex of V and one at base of spur 
| on VI, with one or two very indistinct minute sensoria adjoining it on 
ss the posterior side. Eyes small, ocular tubercle feebly elevated, with 
3 three lenses as usual. 
' 
ee > i 
bo 
Thorax and abdomen unicolorous, prothorax separated from meso- 
thorax by a lateral constriction, in front of which the side margin is 
. subangulate. The dorsum is provided with numerous glands for the se- 
| cretion of a waxy substance, which rises in short columnar tufts from 
each gland, giving an appearance of rows of tubercles. Alcohol soon 
dissolves most of the exeretion, and even obliterates all traces of many 
of the glands. These glands are arranged in regular series, appearing 
in fresh specimens in alcohol as clear smooth spots encircled by a fine 
dark line. There are six longitudinal rows, each with one gland on 
each segment, equidistant on the abdomen, the outer row being at the 
lateral margin. The two middle rows approach at the base of the ab- 
domen, and are close together on the thorax and head, the head having 
four unequal glands in each row, placed within the dusky patch. The 
other four rows do not appear on the head, and are very indistinct on 
the thorax, excepting the prothoracic spot of the outer row, which is 
small but distinct, and below the side margin, those on the other tho- 
racic segments being dorsal. On the abdomen, the outer row consists of 
large lateral spots; the seventh segment has but four spots, two lateral 
