250 LIFE OF THE PLEISTOCENE 



terrace about 70 feet above the river and similar terraces are common in the 

 region." 13 Shimek 14 lists the species found at the above locality, as follows: 



Unto anodontoides JJnio rubiginosus 

 " donaciformis " undulatus 



" elegans Succinea lineala 



" puslulosus Helicodiscus lineatus 



Yarmouth soil, 12-18 inches thick, has been observed, between Kansan drift 

 and loess, in Washington and Hancock townships, near Dalton. 13 



At Sioux City 15 three species of naiads have been obtained from loess-like 

 silt. 



Unio undulatus 

 " rubiginosus 

 " pustulosus 



The mammoth, Elephas species, has been reported from both Cedar and 

 Washington counties. In the former county, 16 from a creek in Springfield 

 Township, (five miles southeast of Clarence) flowing thru Iowan drift underlaid 

 by Kansan loess and till. 17 Here a bed of white alluvial clay is overlaid by 

 gravel, but it is not known from which deposit the mammoth teeth came. 

 In sect. 14, T. 74 N, R. 8 W, Washington County, 18 the bones of this animal 

 were found in an area fifteen feet square in a deposit of black mud and vegetable 

 mold with some clay, six feet below the surface of the ground. 



In Linn County, the following deposits are shown in a section at Bertram, 

 near the mouth of Big Creek: 19 



5. Loess-like loam 3 feet 



4. Sand interstratified with sandy clay 4 ' 



3. Sand, finely and horizontally stratified, fine above, growing coarser below (Iowan) 30 ' 



2. Sand and gravel, with cobble stones 3 ' 



1. Slope of fine whitish clay to water in creek 6 



Height of section 46 ' 



In a gravel pit belonging to the C. & N. W. R. R., across the creek from the 

 above section, coniferous wood was found between numbers 2 and 3. Bones 

 of mastodon, mammoth, and buffalo are reported to be frequently found in 



13 Bain, Geol. Surv. Iowa, VIII, pp. 340; 336; 348. 



14 Proc. Iowa Acad. Sci., V, pp. 37, 44; Hay (Iowa Geol. Surv., XXIII, p. 70) states that 

 Shimek refers the majority of these shells to the work of the aboriginal inhabitants, and they 

 are therefore not listed with the Yarmouth fauna. 



36 Shimek, op. oil., pp. 37, 44. 



16 Norton, Geol. Iowa, XI, p. 377. 



17 Gass and Pratt, Proc. Daven. Acad. Sci., Ill, pp. 177-178. 



18 Anderson, Augustana Lib. Pub., No. 5, p. 26. 

 18 Norton, Geol. Iowa, IV, p. 173. 



