80 THE REPORT OF THE No. 19 



surface is rougli like the leaf not glossy. (4) The part of the leaf around the 

 base is quite normal in appearance, showing no signs of being weakened 

 through lack of nourishment. TJlmus pubescens. — Plate C, fig. 8. 



Hollow, cock's comb-like, thin walled gall; on the upper surface of the 

 leaf. Cockscomb Gall — Colopha ulmicola (Fitch) — Plate I., fig. 5. Ulmus 

 americana. 



A pulpy thickening of the tissues on the under surface of the leaf, 

 extending for some distance along the midrib. Causes the upper surface to 

 double on itself instead of expanding in the ordinary way. Leaf Fold Gall — 

 Cecidomyia ulmi (Beutm) — Plate A., fig. 1. Ulmus americana. 



Curling and gnarling of the leaves forming thereby a sort of pseudo-galL 

 Woolly Aphid Leaf Gall — Schizoneura americana (Eiley) — Plate Q., fig. 1. 

 Ulmus racemosa. 



B. — Galls on the stems. 



Aphids clustering on the limbs and trunks, causing a knotty unnatural 

 growth of the wood. Woolly Aphid Stem-gall — Schizoneura Rileyi (Thomas). 

 Ulmus americana. 



Small green to yellowish pocket-galls, more or less spherical, usually on 

 the upper side of the leaves. Elm Pocket Gall — Eriophyes ulmi (Garman) — 

 Plate H., fig. 5 and 6. Ulmus americana and U. Racemosa, 



An erineum on the under side of the leaf ; white at first changing to 

 brown. Trichomes simple, tangled. Rock Elm Erineum Gall — Eriophyes 

 sp. — Plate H., fig. 3. Ulmus racemosa. 



A very large pouch-gall on the leaves, commencing as a cone or deep 

 dimple. Eriophyes sp. — Plate L., fig. 6. Ulmus pubescens. 



A cone-shaped pouch gall resembling those on Tilia and much larger 

 than Eriophyes ulmi. On the upper surface of the leaf, often very many on 

 a single leaf but thickest along the midrib usually; shape irregular but 

 usually tapering towards both ends and twice as long as thick, average 

 length being about 5 mm., and average thickness about 2-2.5 mm.; color 

 green. Eriophyes sp. — Plate L., fig. 5. Ulmus americana. 



Affecting Evergreens. 



Irregularly oblong gall, situated near the base of the needle on the new 

 growth. Balsam Fir Needle-gall — Cecidomyia halsamicola (Lintner) — 

 Plate A., fig. 3. Abies balsamea. 



Oval swellings on the twigs of various species of Spruce. Spruce Gall 

 louse — Chermes ahietis — Picea nigra, P. excelsa and P. alba. 



The gall consists of an enlargement of the smaller branches. Red Pine 

 Stem Gall — Podapion gallicolla (Riley) — Pinus resinosa 



Affecting False Nettle. 



An elongate, fusiform swelling of the stalk. False Nettle Stem Gall — 

 Cecidomyia (?) hoehmerio'. (Beutm) — Bcehmeria cylindrica. 



Affecting Ginseng. 



Spherical or irregularly cylindrical, brown galls upon the roots. Gin- 

 seng Root Gall. Aralia nudicaulis. 



