180 1.] 53 



Synopsis op the Oak-galls. 



I. Ou leaves. 



A. Formations of a definite, constant form, fastened to the leaf by a very 

 small portion of their surface (except No. 10) and lohich can he 

 taken off without carryhifj a portion of the leaf with 'them; fasten- 

 ed (except No. 7 and 8) to the underside of the leaf. 



Globular galls, consisting of a smooth shell with a single kernel 

 in the centre ; the space between both being filled with a spongy, 

 or cellular substance, or with filaments radiating from' the ker- 

 nel to the shell. 

 With the spongy substance; diameter of the gall about l.n. 



1. Red oak; gall of Cynips conjluens, Harris. 



Black oak; ") analogous galls; gall-fly also very siin- 



Black-jack oak; j ilar; is it different ? 

 With the cellular substance; diameter of the gall 0.15 — 0.2. 



2. Live-oak; gall-fly unknown. 

 With the filaments. 



Diameter about an inch ; filaments not very dense, without 

 silky gloss. 



3. Red oak; gall-fly unknown, perhaps C. conjluens Fitch 



(non Harris). 

 Diameter three quarters of an inch or less; filaments silky. 



4. Post oak; Cynips quercus centricola. 0. S. 



Subglobular galls with a thick hard shell and with a network of 

 lines on the surface; diameter 0.25 — 0.4. 



5. White oak; Cynips qiiercus p)isum Fitch. 



Cylindrical, tubular gall, with spines on the outside. 



6. Post oak; Cynips quercus tuhicola 0. S. 



Spindle shaped, petiolate galls, the petiole being the prolonga- 

 tion of one of the leaf- veins ; frequently on the edge of the leaf. 



7. Red oak; Cynips quercus coelehs 0. S. (the supposed 



male of C. conjluens Harris.) 



8. White oak; Cynips quercus fusiformis O. S. 



Wooly excrescences. 



Rounded, wart-like; apparently with a single kernel. 



9. Post oak; Cynips quercus verrucarum 0. S. 



White oak; ■» distinct from the former; gall 



Swamp chestnut oak; J flies unknown. 



