44 THE BIOLOGICAL REVIEW 



ENTOMOLOGY. 



CANADIAN GALLS AND THEIR OCCUPANTS. 

 DIPLOSIS HELIANTHI, N. S. 



Galls found in the leaf axils, on the upper third of the stems, 

 of Helianthus decapetalus and Helianthus divaricatus, growing in 

 open woods or in shaded situations ; from i — 10 galls in an axil, 



GALLS OF DIPLOSIS HELIANTHI N.S. 



firmly attached to the stem by an expanded base, projecting in 

 various directions, usually upwards, often at right angles to the 

 stem and occasionally downwards ; galls from 10 — 25 mm. long, 

 and from 1-50 — 5 mm. in diameter, curved more or less regularly 

 from a radius of 10 mm. to nearly straight, usually more or less 

 cylindrical, occasionally flask shaped, widest at the base, 



