46 The Ohio Journal of Science [Vol. XVI, No. 2, 



the tip thin, spHtting into a fimbriate condition. Attached by a 

 minute central pedicel, no trace of a saucer-shaped structure 

 developing around the base. Galls greenish to red and purple 

 tinted. Uniformly being covered with sparsely distributed 

 short hairs. Interiorly two chambered, the larval chamber 

 proximal and occupying nearly one-half of the gall. Walls 

 including the partition comparatively thin. Surface of leaf 

 opposite gall slightly raised with reddish tint. 



Collected in Athens County, Ohio, on //. alba, August. 



Type specimens at Ohio State University. 



9. Cecidomyia sp. Cecidium nov. 



On leaf, under side, elongate conic, asymmetric, the axis 

 lying horizontal or parallel with the leaf blade plane. The tip is 

 invariably strongly recurved upward and backward. The side 

 of the proximal part of the gall lying against the leaf is flat- 

 tened and rests close against the leaf and vein ; the galls always 

 spring from the side of a vein. Size variable from 2 mm. in 

 length to 4 mm. this measurement distally not being made to 

 the tip but merely to that part of the recurved terminal portion, 

 farthest from the base. The larger specimens measure 13^-2 

 mm. in width at the proximal end. Light green to nearly 

 white, or sometimes roseate tinged. Very smooth. Walls thin 

 distally thickening toward the basal end. 



Not uncommon on H. alba in Hocking County, Ohio, July. 



Type specimens at Ohio State University. 



A gall, somewhat similar and probably a variety of the 

 above was collected on II. glabra, (Fig. 9a.) 



Cylindric-conic, sharply bent over against the leaf, atten- 

 uate distal part short, not recurved, 3)^ mm. long. Smooth, 

 white like ivory. Wall rather thick, hard. Base of gall in 

 shallow saucer-like depression against the vein. Interiorly the 

 ■distal end is choked with coarse trichomes. 



10. Cecidomyia sp. Cecidium nov. 



Leaf, under side, distal | of gall dome-shaped with 3- many 

 triangular sides, the flaring base resting on the proximal, con- 

 stricted or saucer-shaped \', 2-3 mm. high, 3-4 mm. wide. Tip 

 attenuate, not sharp pointed, however. Light green to yel- 

 lowish green, the tip darker, reddish to black. Surface smooth 

 tinder lens. Larval chamber spherical, surrounded by scler- 



