rAi.i.-c.r.oi 0(}^ ok cki a\ i,ia-s ridck. ,):, 



linio. th()tii:li not ;il\v:iv>. scpnr.-ilrd t licrdroiii hv i)c(ls of s.mikI 

 :ip[);ir('iitly derived Iroiii lli<' tcit i.iiy deposits of tiic <ir(iiiii- 

 jjicent rcii'ioii. Tin' (liar.utcristic lo-ss-kiiKlclM'ii ;ir(' present, 

 l)nl diil'erent Ironi t liose of t !ie noii !i in Ix-inii' solid ■•md nevei' 

 hollow. The ridii'e represents ;i mass of (pialeni;t)-y and tei'- 

 tiary sands and clays that haxc eseajjed, thns fai-, tin' liicat 

 ero.sion to which tiie wliole region has lieen snl)jected since 

 tertiary times. It repres(>nts, therefore, the platean of ter- 

 tiary Ix'ds which resnlted from the retirement of tlie (Jnlf in 

 tlie early (piaternary. There is little of economic \alne in 

 these deposits, althono-h the shell ma.rl of one oi- two localities 

 promises to have some local valne. Xo mineral deposits of 

 any moment are to he fonnd in the ridi;'e. and its top is of 

 little airricnltural valne hecanse of the difiienlty of tillinii'. 

 The pa[)er was to he considered as tentative only a.s an addi- 

 tional season of field work was needed to settle some facts 

 conneeted with the ^enesis of certain sands thonirht to he ter- 

 tiary in age. The final results will ai)pear in tlie annual re- 

 ports of the Arkansas Geologic Survey, under the auspices of 

 which oraaiii/ation the work was done. 



CYNIPIDS AND CYNIPIDOUS GALLS ON OAKS 

 COMMON TO IOWA. 



['A PROF. C. 1*. Gll.I.K J ll-.. 



l,.i/>Stf<Ii{.\ 



For full scientific descrii)tions of the species herein men- 

 tioned see the Report of the Michigan Agricultural Society 

 for 1888. 



Andncus folid/ormis, n. sp. The galls of this species occnr 

 on the under side of the leaves of the white oak {Q. alba). 

 They consist of snndl wait-like projections which spread out 

 in a leafy expanse on all sides so us to remind one of the 

 (rorolla of a rotate flower. Rare. The fly measures about 



[Pkcc. 1. A. S., 1887-9. 1 53 I February «9. 1890.] 



