316 =. W. Hilgard on the Quaternary of Mississippi. 
quently less pervious, the ferruginous solution, unable to pene- 
trate, has aggregated into nodules of limonite ore ($42). On 
f 
of hornstone pebbles (which passes through all gradations of 
fineness into the common ferruginous sandstone of the hilltops) 
gular fragments mostly fit each other, as though produced by 
the contraction in drying, of a gelatinous mass, The cement of 
this breccia is brown iron ore which fills the interstices and has 
colored to the depth of one-tenth to one-eighth of an inch, the 
prone of the hornstone fragments. (See also § 72, and mee 
posi 
common occurrenee, They are, however, always prostrate. : 
have attempted to trace to its origin the report mentioned by 
ges at times, 
those same agencies have doubt 
e limestone fragments coh 
caleareous ingredients have 
