No. 34-] HEMIPTERA OF CONNECTICUT: APHIDIDAE. 327 



2. Joint vi always with annular sensoria 3 



Joint vi without annular sensoria. Distal sensoria irregular in 



form, its membrane bearing islands of chitin populi-transversus 



(Sexuparae) 



3. Combined length of iii, iv, v and vi equal to or less than that of 



hind tibia. Less than fifteen sensoria on iii. V usually shorter 



than vi 4 



Combined length of antennal joints iii, iv, v and vi greater than that 

 of hind tibia. More than fifteen sensoria on iii. Usually about 



twenty. V and vi subequal longicornus n. sp. 



(Fundatrigenia) 



4. Joint iv of antennae with from one to three, rarely four, sensoria. 



More than 60% with less than four 5 



Joint iv of antennae with variable number of sensoria. Less than 

 60% with less than four 6 



5. Antennal coefficient less than coefficient of vi populi-globuli 



(Fundatrigenia) 



Antennal coefficient greater than coefficient of vi populi-venae 



(Fundatrigenia) 



6. Joint V of antennae with from five to seven sensoria. Most fre- 



quent member six bursarius 



(Fundatrigenia) 

 Joint V of antennae with two to six sensoria most frequent number 



three to five populi-caulis 



(Fundatrigenia) 



P. bursarius (Linnaeus). 



Syst. Nat, Edn. 10, 453, 1758. 

 P. populi-caulis Fitch. (PI. xi, 2.) 



Nox. and Ben. Ins. N. Y., v, 845, 1859. 



Hartford, 11 July, 1904; on poplar, Farmington, 11 Aug., 1909 

 (W. E. B.). 



P. populi-globuli Fitch. 



Nox. and Ben. Ins. N. Y., v, 850, 1859. 

 P. populi-transversus Riley. 



Bull. U. S. Geol. Geog. Surv. Terr., v, 15, 1879. 

 P. populi-venae Fitch. 



Nox. and Ben. Ins. N. Y., v, 851, 1859. 

 P. longicornus Maxson, n. sp. 



Stem mother about 2.088 mm. x 1.827 mm. Color pale, yellow- 

 ish vi^hite. Wax pore plates normally arranged for the genus ; 

 variable in size. Those at margin and on posterior segments of 

 abdomen largest. 



Antennae .486 mm. long. Fourth joint distinctly imbricated. 

 Sensoria at distal end of iii and iv oval, fringed with celia. 



Length of segments as follows : i, .069 mm. ; ii, 0.69 mm. ; iii, 

 .208 mm. ; iv, .139 mm. Length of front femora, .356 mm.; 

 tihiae, .295 mm.; tarsi, .104 mm. Length of posterior femora, 

 .487 mm.; tibiae, .435 mm.; tarsi, .139 mm. 



Alate (second generation) viviparous females when freshly 

 removed from galls have the abdomen a creamy yellow, thorax and 

 head dark, almost black, with a bluish tinge. Legs and antennae 



