PERGANDE NORTH AMERICAN PHYLLOXERIN^. 197 



above the basal one-fourth, is rather small and but little project- 

 ing, while the latter is about as long as the basal section below 

 the indentation ; the differences in the galls will, however, readily 

 separate the two. Ph. devastatrix forms a stem- or bud-gall 

 approaching that of perniciosa, whilst this forms a leaf -gall 

 approaching that of c.-septum. It comes also very near c.-inter- 

 media, to which it appears to be most closely related, though the 

 galls have no resemblance to each other. 



Phylloxera picta Pergande, n. sp. 

 PI. II., fig. 10; PI. IX., fig. 48; PI. X., figs. 61-63. 



The galls of this species resemble very much those of c.-septum, 

 though ordinarily smaller, much more flattened, and to all 

 appearances entirely destitute of a dividing membrane. The 

 insects are also smaller and paler and exhibit some characters 

 which tend to separate it from that species. 



The transverse diameter of the gall varies between 3-6"""- and 

 the vertical diameter between 2-3"""- It is quite flat on both 

 sides, though somewhat more elevated and more convex on the 

 upper, with a more or less distinctly depressed ring surrounding 

 the base of the nipple. Both sides of the gall are provided with 

 a short, conical nipple, each closed till maturity, and furnished 

 inside and generally also at the tip with fine pale hairs. The 

 lower nipple always remains closed, while the upper opens in a 

 round or oval mouth, split into several very short, recurved bracts 

 covered with fine pubescence. The walls of this gall are very 

 thin and semi-transparent so that the insects can be seen moving 

 ■ about if held towards the light. The color is variable. Some 

 are quite dark-green with a faint purplish shade and with the 

 nipple and a ring around its base dark red. Others are of the 

 color of the leaf or slightly paler, with a faint purplish ring sur- 

 rounding them, the nipple and the depression surrounding its 

 base pale buff or pale clay-yellow. Another variety is more or 

 less pink, its margin yellowish or concolorous with the leaf. 

 Still others are pale greenish-yellow with a faint purple ring 

 surrounding the still darker nipple, besides many other variations. 

 The under side is uniformly paler than the leaf and the nipple 

 yellowish. 



[Proc, D. a. S., Vol. IX.] 24 [Sept. 21, 1903.] 



