Leaf, under side, arising from a shallow cup-like structure. Shape of a slender horn, slightly curved, 5-7 mm. long, 1¼ mm. wide at base. Light green at base, changing to yellow, the distal ⅔ of the gall a deep brown. No demonstrable opening at the end. Walls thin. Surface smooth, under lens minute longitudinal striations evident. Very little discoloration on the upper side of the leaf to mark the location of the gall beneath. Resembles Caryomyia tubicola O. S. but is certainly a different species.
Collected in Hocking County, Ohio, July, on H. alba.
Type specimens at Ohio State University.
28. Cecidomyia sp. Cecidium nov.
On leaf, generally upper side, delicate, small, sub-cylindric galls, standing erect, 2-2½ mm. high, less than 1 mm. wide, constricted proximally to the slightly flaring base. Distal end marked off by a circular ridge, in the center of which is a rounded nipple. This latter turns dark early. Gall light green, at length turning brown. Arises from intervenal areas between the smaller veins. On the under side of the leaf the gall above is indicated by a minute dark area. Attached to leaf by minute central pedicel.
Collected in Hocking County, Ohio, on H. alba in July.
Type specimens at Ohio State University.
29. Cecidozoon (Type undetermined.) Cecidium nov.
On leaf, under side, rather large, pouch-like gall (5-6 mm. long) arising from a principal vein. Shaped like a stout gourd, it is bent over nearly recumbent against the blade of the leaf. 2-2½ mm. wide. The proximal end is sharply constricted at the minute point of attachment. The walls when collected were light brown in color, sparsely covered with short white hairs. Walls very thin and when dry brittle. Interior surface smooth. Inconspicuous on the upper side of the leaf, except for the minute pore next the vein. Two specimens from the same leaflet.
This gall differs so markedly from all the other cecidomyidous galls of the hickories, that I am not certain just where to place it. They contained no occupants of any kind.