2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 61. 



be determined by the use of the subjoined keys because it is liable to 

 be a new species, and yet it has seemed best to make the present paper 

 somewhat monographic in treatment, as in the previous paper on 

 root galls, that it may serve as the basis for future work. No extended 

 bibliography of the described species has been given. The text figures 

 are by Miss E. T. Armstrong and the photographs are by the author, 

 except figure 9 on i^late 3, which is from negative 774, Eastern Station, 

 Division of Forest Insects. 



SYNOPSIS OF THE ACOBN GALLS PRODUCED BY AMERICAN CYNIPIDAE. 



1. Galls on or in the tissue of the acorn cup and not involving the acorn. 



A. Large, globular, thick-walled, hard, mottled brownish or reddish gulls 



produced on the side of the acorn cup, easily detached, droppinu; to 

 ground iu the fall (pi. 1, ligs. 1, 2). Always on red oaks. 



On Q. rubra, nana, vclutina, coccinea. 15-2.5 mm. in diameter. 

 Shrivel in drying and becomes very hard. 



Amphibolips prunus Walsh, p. 5. 

 On Q. marilandica. 25-35 mm. in diaiucler. Do not wrinkle in 



drying Amphibolips gainesi Basseti, p. 4. 



On Q. laurifolia, pficUos. 7-11 mm. in diameter. 



Amphibolips fulginosa Ashmead. p. 4. 



B. Smaller galls more or less embedded in the tissue of the cup, often 



slipping out on to the ground in the fall when mature. 



On Q. bicolor. Ellipsoidal white cell 4 by 7 mm. almost hidden 

 in a fimbriate recess in the side of cup (pi. 1, fig. 3). 



Andricus fimbriatus, new species, p. 20. 

 C Cell in tissue of acorn cup and not separable from it. 



On Q. hicolor. Cell in bottom of cup under acorn causing it to 

 become lopsided Undescribed species (pi. 5, fig. 20). 



2. (Jails known as " pip " galls produced between the acorn and the cup. 



A. Pip galls alongside full-grown acorn (often reduced in size) (pi. 4. 



fig. 15). 



On Q. rubra, velutinu, coccinea. 



Callirhytis operator (Osten Sackeu) agamic generation, p. 23. 



B. Galls alongside the immature acorns of red oaks (pi. 3, figs. 7. 8; 



pi. 4, figs. 14, 16, 17.; pi. 5, fig. 18). 



On Q. coccinea. On the one year old acorns in early spring. 



Secrete honeydew Callirhytis balanosa, new species, p. 19. 



On Q. velutina. In fall alongside immature acorns. 



Callirhytis balanoides, new species, p. 27. 

 On Q. marilandica. In fall. Longer tlian broad and deeply 

 embedded alongside immature acorns, the cup twice normal 

 size. Secrete honeydew. 



Callirhytis balanaspis, new species, p. 22. 

 On Q. marilandica. In fall. About as broad as long, mostly 

 protruding from young acorn cup which is not enlarged. Se- 

 crete honeydew Callirhytis balanopsis, new species, p. 2t>. 



On Q. affrifolia, idslizenii. Secrete honeydew. 



Callirhytis carraelensis, new species, p. 20. 



