192 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



In clusters: 



When fresh fleshy, pure white, or rosy red at apex, fig-shaped, growing quickly 

 in spring and after insects emerge either rotting or shriveling into a hard but 

 not woody mass. Galls of this eort, producing the sexual generation, seem to 

 be limited to the genera Trigonaspis and Belonocnema. While the flies differ, 

 it is not possible at present to separate the different kinds of galls except as the 

 host oak and locality may be known. Other hosts for these species listed and 

 other species will no doubt be found — 



On Q. alba, stellata, chapmani 8. Trigonaspis radicola (Ashmead), p. 203. 



On Q. douglasii 7. Trigonaspis obconica Weld, p. 202. 



On Q. gambelii, in Santa Catalina Mountains, Arizona. 



9. Trigonaspis fumosa Weld, p. 204. 

 On Q. reticulata in Santa Catalina Mountains, Arizona. . Probably No. 9, p. 205. 

 On roots of an unknown oak in Utah and Colorado. 



10. Trigonaspis pumilivenlris (Bassett), p. 205. 

 On Q. virginiana. Fresh galls probably similar to above and drying to a 



dark brown hard mass See No. 35, p. 238. 



On Q. laceyi, Texas. Dry galls 5 mm. in diameter, smooth. 



42. Weld No. 407, p. 242. 



On Q. laceyi and virginiana, surface pubescent 43. Weld No. 408, p. 243. 



Tissue not so spongy, at least part of gall ultimately becoming brittle or woody 

 and persisting: 



Individual galls less than 6 mm. in diameter — 



Cluster of 30-100. Cells fig-shaped with a slender stalk, ribbed surface 

 and brittle wall, 6 mm. long by 4 mm. in diameter. Q. rubra, 



texana, catesbaei, myrtifolia 20. Callirhytis enigma Weld, p. 219. 



On Q. stellata. Appearance when fresh unknown. Disintegrates and 



leaves about 20 hard brittle cells Probably No. 19, p. 217 . 



Cluster of scores of elongated angular wedge-shaped cells with rounded 

 ends which decay away. Cluster measures up to 6 cm. in diameter 

 and resembles ear of corn. White when fresh, becoming tan and brit- 

 tle. Q. rubra, texana, catesbaei, marilandica, brevifolia, nigra, myrtifolia. 

 6. Dryocosmus favus Beutenmueller, p. 200. 

 Onion-shaped, pointed, longitudinally striate, white or rosy when fresh, 

 later tan and brittle. Base of sprouts of Q. rubra, velutina, texana, 

 marilandica, falcata, laurifolia, catesbaei, brevifolia, myrtifolia. 



11. Biorlnza caepulifornm (Beutenmueller), p. 206. 

 Individual gall, averaging more than 7 mm. in diameter — 



Hemispherical cluster up to 8 cm. in diameter, consisting of from 1 to 35 

 galls, each 2-3 cm. in diameter. White and fleshy, later tan, rough, 

 cavernous within and disintegrating in time, so as to leave a rough 

 cell at base, persisting on bark for years. Monothalamous. Q. ivisli- 



zeni, californica, agrifolia. 



22. Callirhytis apicalis (Ashmead), p. 222. 



Hemispherical cluster of a few galls, measuring up to 3 cm. Tissue of 

 gall dense, tawny yellow. Q. chrysolepis. 



26. Callirhytis fulva Weld, p. 226. 

 Bullet galls on base of shoots, resembling Disholcaspis globulus (Fitch) 

 in appearance and texture. Inner cell distinct and often free — 

 On Q. alba, galls often reddish. . .3. Disholcaspis globosa Weld, p. 196. 



On Q. prinus See note under No. 3, p. 197. 



On Q. stellata and margaretta. Galls reddish and becoming wrin- 

 kled on surface when dry. 



5. Disholcaspis terrestris Weld, p. 198. 



