298 LIFE OF THE PLEISTOCENE 



occidentalis) was obtained from the old soil material. Fossiliferous loess occurs 

 in other parts of the Danville region. 



Helicina occulta occurs in Gallatin County with other mollusks. 68 At 

 Freeport, Stephenson County, Succinea avara is reported from the loess. 69 

 Mollusks have also been reported from the loess of White, Hamilton, Hender- 

 son, and Mercer counties. 



Loess overlies Sangamon soil in Sangamon County, and rests directly upon 

 it, except in a few cases where sand separates the two deposits. It is fossili- 

 ferous in many places. The loess in this county doubtless includes both the 

 Sangamon and the Peorian intervals. The fossils are not specifically listed. 70 



Fossiliferous silt or 'oess covers portions of Boone and Ogle counties. Lev- 

 erett says: 71 "at the Village of Stratford, five miles east of Polo, the railway 

 exposes a bed of fossiliferous silt at the base of the lowan drift, resting on an 

 old land surface formed on the Illinoian. ... In two other localities fossili- 

 ferous silts have been found at the base of the lowan, one being in the railway 

 cuttings on the I.C. immediately west of Irene . . . and another in the rail- 

 way cutting of the Chicago and Northwestern, . . . one mile east of Belve- 

 dere. Here, as at Stratford, the fossils are mainly of the one species (Succinea 

 avara)." These deposits should probably be referred to the post-Illinoian 

 loess or Sangamon interval. 



The loess (also called a compact silt) extends eastward in a practically 

 continuous sheet from Illinois over southern Indiana, southern Ohio and 

 neighboring portions of Kentucky and West Virginia and is the superficial 

 deposit as far north as the border of the Wisconsin drift sheet. It is known 

 to underlie the Wisconsin drift, numerous exposures having been found beneath 

 that drift. 72 It is called white clay in the early Ohio reports and slush land 

 in the Indiana reports. As in Illinois, this loess probably includes both the 

 Sangamon and the Peorian intervals altho all have been referred to the lowan 

 age by Mr. Leverett. 



e. Vertebrates 



Mammals have been reported from various deposits of Sangamon age. In 

 Madison County, 73 above the City of Alton, the remains of a mastodon were 

 found 30 feet below the surface, near the bottom of the loess, where it was 

 separated from limestone by 2-3 feet of local drift (Illinoian). The loess above 

 contained land and fresh water shells. A mastodon was also found in Peoria 



•"Geo!. 111., VI, p. 213. 



ts Hershey, Amer. Journ. Sci., (iv), IV, p. 98. 



'° Shaw and Savage, Tallula-Springfield Folio, p. &. 



" Leverett, Illinois Glacial Lobe, p. 138. 



72 Leverett, Mon. XLI, p. 295. 



» Worthen, Geol. 111., I, p. 315. 



