This form is so different from the other itonid galls of the hickory that the writer is inclined to place it here tentatively. It is very similar to _Phylloxera caryævenæ_ Fitch, with the exception that the hyperplasia extends below the leaf, while in the phylloxera gall it is developed on the upper side. The writer has observed orange colored larvæ in the aphid galls, but they were not definitely determined to be itonid. Since this type of gall has not since been reported as definitely caused by itonid larvæ, it is barely possible that Osten Sacken described the empty phylloxera gall above mentioned containing inquilinous itonid larvæ. The writer found many of these galls deserted by the aphids in the middle of July and Pergande states that the aphid nymphs begin to leave the galls in July. At this time, these galls are a “pale yellow” color as described for the “cynipsea” gall. The writer’s observations were made in southern Ohio, while Osten Sacken’s were made in the vicinity of Washington, D. C. Osten Sacken, Lowe’s Monogr. Dipt. N. Am. Pt. 1. p. 193. 1862. 5. =Cecidomyia= sp. Leaf, under side, double chambered conic or depressed (Fig. 5a) gall. The latter condition is perhaps the more usual. In these forms, the conic tip is sunken in the central fovea, the gall only measuring from 1½-2 mm. vertical diameter. The conic forms are as though the tip was pulled out destroying the fovea. These often measure 5 mm. in height. The width of the galls varies from 3-5 mm. Very light green, or when older yellow to red, surface roughened with low tubercles as seen with lens. Inner chamber sub-conic with short mucronate tip. Walls of both chambers thin and smooth, outer wall slightly sticky. Base of gall flat, arising from a definite pedicel, resting in a cup-like depression, which is formed in a definite hyperplasia intercalated in the leaf. Above, this hyperplasia is evident as a raised circular area, 2½ mm. diameter, in the center of which is a minute light colored papilla. Rather common on _H. alba_. Collected in Hocking and Athens counties, Ohio. This double-chambered gall cannot be _Caryomyia inanis_ Felt, for it is neither “globose and small.” The author describes elsewhere a specimen which fits that description and is very probably produced by the cecidozoon just mentioned. Absolute certainty, it must be remembered, can only be obtained by checking the reared adult insects with the original descriptions. Sears described this gall from Cedar Point, Ohio, under the name _C. inanis_. Sears, Ohio Nat. 15:380, pl. 18, Fig. 18. 1914. 6. =Caryomyia inanis= Felt. “Globose, thin-walled with a false chamber at the apex. Dia. 2-3 mm.” Felt. In my material, the false chamber is large, occupying more than half of the gall. The gall is slightly balloon-shape, 2½ mm. high. Surface perfectly smooth. Collected, Hocking County, Ohio, on H. ovata.