THE KANSAN ICE INVASION 



269 



shells described as forming the distinct line probably represents the Yarmouth 

 interval. Greger lists 22 species from the loess deposit. 



Polygyra albolab-risfa) 

 appressafa) 

 appressa, small var.(c) 

 elevata(a.) 

 multilineata(x) 

 thyroides(c) 

 zaleta?(c) 

 fraterna(c) 

 monodon(c) 

 hirsuta{c) 

 toides arborea{r) 

 " minuscula(c) 

 (a) = abundant 



Zoi\ 



(c)= common 



Pyramidula solitaria(c) 

 alternata(a) 

 allernata, small var.(c) 

 Gastrodonla ligera(t) 

 Helicodiscus parallelus{c) 

 Vallonia pulc)tella{i) 



" species indet.(r) 

 Biftdaria contracta{c) 

 " armifera(c) 

 " procera?(i) 

 Caryckium exile{&) 

 Helicina occulta(c) 



(r) = rare 



7. KANSAS 



Examples of the Yarmouth interglacial interval are rare in Kansas. Swal- 

 low 78 records the bones of a horse from near Marysville, Marshall County, from 

 a well 45 feet below the surface, in beds of stratified sand which lie beneath the 

 bluff formation (loess) and above the drift. The species is not named. 



8. ILLINOIS 



In Illinois the Yarmouth is well developed in many localities and the infor- 

 mation at hand is sufficient to lead to the conclusion that it underlies the Illi- 

 noian drift thruout the greater part of the State. The following section is 

 typical of the order of the strata in the western counties: 79 



Section of well at Pa'na, Christian County 



Soil and clay (loess) 11 feet 



Blue clay (loess) 4 " 



Sand and gravel (Sangamon) 12 " 



Hard red clay (containing wood) Illinoian 21}^ " 



Blue clay (Illinoian) 57 " 



Black soil or forest bed (Yarmouth) 2)4 " 



Blue clay (Kansan) 19 " 



Height of section 127 feet 



In Ford County a well section indicated a different succession of strata. 8 " 



Yellow till (Wisconsin) 10 feet 



Soft blue till (Wisconsin) 30-40 " 



78 Trans. Acad. Sci., St. Louis, H, p. 418. 

 7 » Leverett, HI. Glacial Lobe, p. 107. 

 80 Op. cit., p. 663. 



