CECIDOMYIA. 199 



being coalescent; their intervals are indicated only by longitudinal 

 crests of erect hairs ; a reddish spot before the scutellum ; the lat- 

 ter brownish with two black streaks at the basis ; sternum brown- 

 ish; the rest of the thorax, as well as the abdomen, are of a bright 

 red, especially in the ?, where this red color is more apparent, the 

 abdomen being so much more distended ; dorsal segments of the 

 abdomen brown (which color is produced by numerous and exceed- 

 ingly minute scales, appressed to the body); stem of halteres pale, 

 knob obscurer ; basal half of femora pale ; their apical half, tibiae 

 and tarsi brownish ; wings margined with a brown pubescence 

 anteriorly and round the apex, especially in the ?; cross-vein not 

 apparent; the second longitudinal vein reaches the margin a short 

 distance before the apex. 



17. C. ocellaris, n. sp. Ocelliform, red spots on the leaves of 

 the red maple {Acer rubrum). They have about 0.3 in diameter ; 

 the margin is bright cherry red, and there is a round patch of the 

 same kind in the centre. The interval between them is pale. They 

 appear brighter on the upper side of the leaf; on the under side 

 in the centre is a small depression occupied by a small, transpa- 

 rent, colorless larva. I found them in this state at the beginning 

 of June. Later in the season I observed that the spots had lost 

 their fresh color, and that the larva had disappeared ; I suppose it 



lAflA. -*• drops to the ground to undergo its transformation. 



18. G. pellex, n. sp. Rounded oblong, succulent, subpellucid 

 galls on the ribs of the leaves of the ash (Fraximis americana). 

 Diameter, 0.15 to 0.2. They are pale green, and the more ripe 

 ones are slightly colored with brownish. The principal convexity 

 is on the upper side of the leaf; on the under side the leaf-rib 

 appears swollen, pale green in the middle, and whitish on both 

 sides. Each gall contains a whitish larva; some of these galls 

 were double. There were one or more (as many as six) galls on 

 the same leaf. Towards the end of June I found many of these 

 galls shrivelled and dry, and suppose therefore that the larvae had 

 gone under ground. A gall apparently similar to this has been 

 discovered on the European ash, and described by Bremi and 

 Winnertz. 



19. G. niveipila, n. sp. Deformation of oak leaves, consisting 

 of a large fold with a white pubescence on the inside. It begins 

 very early in the spring on the young leaves of the white oak and 

 other kinds of oak. The egg is probably deposited on the upper 



