1908 ENTOMOLOGICAL SOCIETY. 79 



Affecting Buttonbtjsh. 



Clusters of small dimples on the upper side of the leaf, 1 to 3 mm. high. 

 Buttonbush Dimple Gall — Eriophyes cephalanthe (Cook) — Plate K., fig. 5. 

 Cephalanthus occidentalis. 



Affecting Chestnut, 



A small capsule gall, on the leaf, more or less spherical and 2-3 mm. 

 in diameter. Chestnut Capsule Gall — Eriophyes sp. — Castanea sativa, var, 

 americana. 



Affecting Cinqtjefoil. 



Oval or spherical galls from 4 to ^ inch in diameter, arising in the axil 

 of the leaves. Cinquefoil Axil Gall — Diastrophus potentillce (Bass) — Plate 

 B,, fig, 5. Potentilla Canadensis. 



Oval or cylindrical swellings from 1 to 2 inches long on the stems usu- 

 ally near the base of the plant, Monothalamous. Cinquefoil Stem Gall. 

 Potentilla norvegica. 



Affecting Currant, 



Red or purple elevations or folds on the upper side of the leaf. Currant' 

 Leaf Gall — Myzus ribis, Linn — Ribes rubrum. 



Affecting Dandelion. 



Irregular, knotty, pithy swellings, forming oblong irregular galls along 

 and surrounding the leaf -petiole ; average length from one-quarter of an inch 

 to fully two inches. Dandelion Petiole Gall — Gilletia Taraxaci, Ashmead — 

 Taraxacum officinale. 



Affecting Dogwood. 



Club-shaped and about ^ to 1 inch long. On terminal twigs. Dogwood 

 Club Gall — Cecidomyia cla'tiula (Beutm.) — Cornus florida. 



Thin-walled circular elevations on the under side of the leaves. Dog- 

 wood Leaf Gall — Lasioptera corni (Felt) — Plate A., fig. 2. Cornus florida. 



Small, nearly oval Gall situated on the petiole of the leaf. Flowering 

 Dogwood Petiole Gall. Cornus florida. 



Affecting Elm. 



A. — Galls on the leaves. 



Round dimples in the backs of the leaves resulting in small elevations on 

 the upper side. About 2 mm. in diameter and surrounded by an areola of 

 lighter green. In the cavity of the gall rests a small, white larva covered 

 with a viscid, transparent secretion. Pimple Gall — Cecidomyiadce — Plate 

 P., fig. 4. Showing larva and gall, 



TJlmus americana, 



A leafy growth arising from a bud and resembling the Pine Cone Willow 

 gall but more nearly spherical and only about ^ an inch in diameter. Remains 

 jjreen during summer but changes to a dark brown in winter. Red Elm 

 Bud-Gall — Plate P., fig. 6. Ulmus pubescens. 



A green plum-like structure on the upper surface of the leaf. About 10 to 

 12 mm. in length and 3 to 7 mm. in thickness. Plum Gall — Pemphigus ulmi 

 fnscus — Ulmus campestris. 



There is a similar gall on Red Elm, but differing in the following 

 respects : (1) It is twice as large. (2) The wall is a little thicker. (3) The 



