THE CANADIAN ENTOMOLOGIST 83 



fall of the year only, on Rumex, on which plant the eggs are laid. 

 The details of this migration from Polygonum to Rumex have not 

 been worked out. 



Macrosiphum tiliae (Monell). 



When in Madison, Wis., the past fall (September 10, 1912) 

 the writer found this rather rare species not uncommon on basswood 

 (1'ilia americana), both green and pink viviparous females, as well 

 as the sexes, being observed. Previous to this collection, he had 

 found this species on only two occasions — July 23, 1908, at Chi- 

 cago, 111.-, only a single winged viviparous female being taken, and 

 July 12, 1909, at the same place, only two wingless viviparous 

 females being obtained. 



Winged viviparous female. (PI. V, figs. 21 — 23.) 



(Described from specimens obtained at Madison, Wis.) 



Green Form: Head pale brownish, eyes black. Antenna' 

 placed on prominent tubercles as shown in illustration; black, 

 excepting segments I and II, which are concolorous with head; 

 reaching beyond tip of body; filament of segment VI much the 

 longest, being about twice the length of III; segment III bearing 

 11 to 16 circular sensoria in a row; segments V and base of VI with 

 the usual distal sensoria. Beak reaching just to coxa 1 of second 

 pair of legs. Thorax dark green. Wings with narrow brownish 

 veins. Media i and media i branching at about one-half the dis- 

 tance from where media 3+4 branches to tip of wing; this, however, 

 not being a constant character. Abdomen pale green, immaculate. 

 Cornicles black, reaching a little beyond tip of cauda, noticeably 

 widened at base, and slightly constricted near tip; the tip plainly 

 reticulated. Cauda pale green, ensiform, sparsely covered with 

 moderately long hairs, and about one-third the length of cornicles. 

 Anal plate rounded. 



Average measurements from four specimens in balsam: 

 Length of body, not including cauda, 2.63 mm., length including 

 cauda 2.79 mm.; width of body 1.01 mm.; length of wing 4.10 mm.; 

 width of wing 1.40 mm.; length of cornicle 0.88 mm., of cauda 0.28 

 mm. Antennal measurements as follows: 



