392 
Indiana University Studies 
Probably thruout most of Alabama and Georgia (and Mississippi?), 
the entire Tennessee River Valley, the Mississippi Valley into southern 
Illinois, southern Indiana, and the Ohio Valley into Pennsylvania. Fig- 
ure 67. 
TYPES. — 23 females and 42 galls. Holotype and paratype females 
and galls in the Kinsey collection. Paratype females and galls in the 
Museum of Comparative Zoology, the U.S. National Museum, and the 
American Museum of Natural History. From 13 miles north of Troy, 
Alabama; galls November 14, 1927; part of the insects November 20, 
1927 ; Q. alba; Kinsey collector. 
FIG. 67. INLAND DERIVATIVE OF C. PEZOMACHOIDES 
Possible extension of known range shown by shading. 
This is very evidently the inland equivalent of the Atlantic 
Coastal Plain variety pezomachoides. The two insects are 
close, and the galls are in many respects similar, but derivatus 
galls are noticeably larger than those of pezomachoides. 
Derivatus insects are most distinct in central Georgia and 
Alabama, but in northeastern Georgia derivatus grades into 
pezomachoides so gradually that the two would not be recog- 
nized as distinct in that part of the country. Further north 
derivatus occurs in the Great Valley of the Tennessee, and in 
the Mississippi and Ohio Valleys in western Kentucky, south- 
ern Illinois, and southern Indiana. In the latter region the 
variety finds its normal northern limit, but thruout the 
northern Middle West the species is represented by variety 
erinacei, which appears to be a hybrid of wheeleri x derivatus 
