1907 ENTOMOLOGICAL SOCIETY. 91 



is held in position by a comparatively small number of filaments whicb radiate 

 from it to tbe surrounding walls. It occurs on tbe Eed Oak (Quercus rubra). 

 Rare. 



White Oak Club Gall (Andricus clavula, Bass). Plate C, fig. 3. 



This is a club-shaped gall situated at the tip of the twigs. It evidently 

 originates in the terminal bud-clusters, which it prevents from developing, 

 though occasionally a few leaves grow out from the gall itself. When mature, 

 it is ^ to 1 in. long, hard and woody in texture, a little darker in color than the 

 Test of the bark, and somewhat grooved and ridged. Very often a second, 

 or even a third, somewhat smaller gall is formed from the lateral buds 

 immediately below. The terminal gall, in the cases examined, was dithala- 

 mous, the lateral ones monothalamous. It occurs on the White Oak (Quer- 

 cus alba). Common in Muskoka. 



Willow Petiole and Leaf -base Gall (Saw-fly) — Pontania desmodioides 

 (Walsh). 



This gall has the form of an oblong enlargement of the petiole, or often 

 of the midrib of the leaf near the base. It is 8 to 15 mm. long and 4 to 6 mm. 

 in diameter. Surface smooth and glossy, like that of the leaf; occasionally, 

 however, it is somewhat rugose and irregular. The gall is solid and of a 

 pulpy texture. It was monothalamous on July 8th, the date of discovery, 

 the cavity being very small and containing a tiny greenish-white transparent 

 larva with a brown head. Occurs on the Willow {Salix lucida). Rare, at 

 Guelph. 



Red Oak Gall {Andricus papillatus). Plate C, fig. 5. 



This gall is red and projects on both sides of the leaf. It is round and 

 about 4 mm. in diameter. Above dark red, below yellowish. About three 

 times the thickness of the leaf. On Red Oak at Puslinch Lake. July. 



Spiny Ball Gall on Wild Rose leaf. 



The gall described as Rhodites bicolor (37th Annual Report, page 70, 

 Plate E, fig*. 2), has been identified by Mr. Wm. Beutenmuller as R. nebu- 

 losus. 



Lepidoptera. 



Golden Oval Stem Gall (Euoosma Scudderiana, Clem.). Pliate' C, 

 fig. 7. 



This gall is situated on the stem and is oval in form, about 1 cm. long 

 and 4 to 5 mm. in diameter. Its surface is similar to that of the stem, but 

 the color is a little darker around the central part. It is pithy in texture 

 and monothalamous. At the date of writing, July 24th, the chamber was 

 small and cylindrical, and contained a single orange-colored larva. The 

 galls are found either singly or often with two united and forming an irregu- 

 lar elongated enlargement. They occur on the Goldenrod (SoUda]go sp.). 

 Common in Muskoka. 



Hemiptera. 



Plum Gall on Elm {Pemphigus ulmi-fuscus). Plate C, fig. 8. 



This attractive looking gall occurs on the upper surface of the leaf and 

 resembles in shape an unripe cherry or plum, there being an upper glossy 

 green drupe-like part and a short stem connecting this with the leaf. The 

 drupe-like part is slightly oblong in most cases and varies in length from 8 to 

 10 mm. and in thickness from 5 to 7 mm. The stem is from 3 to 4 mm. long 

 and 2 to 3 mm. thick. The gall is monothalamous ; a rather thin outer cover- 

 ing about 1 mm. thick and somewhat firmer in texture than the leaf encloses 

 a large, round cavity, in which a single mother insect brings forth her brood 

 of many young. The part of the leaf from which the gall springs is drained 



