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



The lower leaves are more heavily infested due to the fact that 



the insects are apt to reach these first in their flight from the 



ground in the spring. 



Osten Sacken, Lowe's Monogr. Dip. N. Am. Pt. 1, p. 192. 1862. 

 Beutenmuller, Am. Mus. Nat. Hist. Guide Leaflet No. 16, p. 28, Fig. 59. 

 Reprint from Am. Mus. Jour. Vol. 4, 1904. 



14. Cecidomyia sp. Cecidium nov. 



Leaf, under side, distal half conic-attenuate from the bulbous 

 or sub-globular proximal half. Covered with long, coarse 

 trichomes, the longest being half the length of the gall. Tri- 

 chomes brown. Tip of gall generally darker than rest. 3-4 mm. 

 high, 2-3 mm. wide. Cavity sub-spherical somewhat depressed 

 at right angles to axis of gall. Walls relatively thick, especially 

 the proximal part. Apical canal evident in median longitudinal 

 section. Gall attached by short and broad pillar of tissue 

 extending from the leaf into the fleshy base. 



Gypsum, Ohio, August, on //. ovata. 



Type specimens at Ohio State University. 



15. Cecidomyia sp. Cecidium nov. 



On leaf, under side, small, conic galls, generally found in 

 pairs closely appressed to each other but not confluent. Distal 

 attenuate \ rather sharply constricted from the sub-globular f 

 of the gall and generally turned to one side. 2 mm. high, iy2~2 

 mm. broad at base. Yellowish in color, definitely and constantly 

 pubescent. Interiorly the lining of the sub-globular larval 

 chamber is deep blue-black in color. Walls of medium thick- 

 ness. Comparatively large region of the base involved in the 

 attachment of the gall. 



Collected in Hocking County, Ohio, on //. a/ba, July. 



Type specimens at Ohio State University. 



16. Cecidomyia sp. 



On leaf, under side, greatly depressed with central, prom- 

 inent nipple, 3-5 mm. dia. 1^^-23/^ mm. thick (vertical dia.) not 

 including nipple. Light green, smooth. Firm fleshy with 

 central sub-spherical larval chamber whose wall is differentiated 

 from the surrounding tissue. Apical canal through nipple 

 evident. This gall first reported and illustrated by Thompson. 



Thompson, Illus. Cat- Am. Ins. Galls. 1915. p. 56, pL 13, Fig. 228. 



