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



3. Galls double-chambered as seen in vertical median section. 4. 



3. Galls single chambered. 7. 



4. Galls definitely depressed. (5). 

 4. Galls small, sub-globular. (6). 



4. Galls definitely conic. 5. 



5. Elongate gall with'rounded base in definite visible socket. (7). 



5. Shorter gall attached by pedicel from rounded base not articulating with 



definite socket. 6. 



6. Proximal chamber of gall, conic. (5). 



6. Proximal chamber of gall, depressed. (8). 



7. Galls definitely conic; forms having rounded bases, the distal portion is 



sufBciently drawn out to place the cecidium under this class. 8. 

 7. Galls spheric, sub-spheric or depressed. 15. 

 7. Galls sub-cylindric, 23^-3 times as long as wide. 22. 

 7. Galls obconic, i. e., part projecting from leaf is flat topped, constricted prox- 



imally to the pedicel embedded in the leaf. 25. 



7. Blister gall, intercalated in the leaflet, projecting on both sides. Cecidomyia? 



sp. (33). 



8. Small irregular, low, masses of tissue always in axils of principal veins of 



leaflet. Eriophyes sp. (1). 



8. Galls definite structures projecting prominently from leaf surface. 9. 



9. Conic gall generally with strongly recurved tip appearing as though lying on 



side, decumbent. (9). 

 9. Galls erect or tilted, seldom bent over, however, beyond angle of 45. 10. 

 10. Gall with flattened sides, pyramid-like. (10). 



10. Galls with sides flattened. 11. 



11. Proximal half of gall conic, never sub-globular. (11). 



11. Proximal half sub-globular. 12. 



12. Galls smooth. 13. 



12. Galls pubescent. 14. 



13. Galls large, 4-7 mm. long. (12). 



13. Galls small, 1^-4 mm. long. (13). 



14. Trichomes very long coarse. (14). 



14. Pubescence short, fine. (15.) 



15. Galls attached by proximal pedicel embedded in leaf, as seen in a median 



vertical section. 



15. Galls attached by structure extending from leaf into base of gall, which 



remains on leaf when gall falls. 20. 



16. Walls thick, soft. 17. 



16. Walls thin, 18. 



17. Galls smooth, depressed or with upward flaring walls forming a saucer or 



cup-shaped structure distal to the chamber. (16). 



17. Gall globular, finely pubescent like that of a peach. (17). 



18. Surface perfectly smooth, symmetrically sub-spherical galls. 19. 



18. Surface minutely .shagreen-roughened, gall a.symmetric, one side prominently 



extended laterally. (18). 



19. Small galls, 23^ mm. dia., nipple expanded and flattened resembling the end 



of a bottle. (19). 



19. Larger gall, 3-4 mm. dia., nipple short, pointed. (20). 



20. Thick-walled, particularly the distal end, covered with heavy tawny 



pubescence. (21). 

 20. Thinner walled, pubescence veryshort, puberulent. 21. 



20. Very smooth. (22). 



21. Depressed (not over 3 mm. high) with column extending through center of 



chamber. (23). 

 21. Globular, 4-5 mm. high. (24). 



21. Definitely balloon-shape. (25). 



22. Base embedded in socket. 23. 



22. Base not embedded in socket. 24. 



23. Round-conic at tip. Caryomyia tubicola. (26). 

 23. Tapering to point, horn-like. (27). 



