POSTGLACIAL BIOTA OF THE GREAT LAKES REGION 121 



a dark color. In some instances, a faint approach to stratification may be 

 seen, showing more prominently at the junction of the sand and clay. The 

 floor of the valley in which I find these forms is not more than eight or ten 

 feet above the present level of Lake Michigan. In no case have I found any 

 formation overlying the one containing the shells, such as till, clay, etc., but 

 always as previously described" [in letter]. 

 The shells found by Mr. Ball are as follows: 



Sphaerium sulcatum Planorbis parvus 



Physa species, fragments Planorbis hirsutus? 



Pyramidida alternata, young 



3. Strata of Uncertain Age 



There are several records which cannot be definitely correlated with any 

 of the lake stages. Slocum's record of elephant remains at the base of the blue 

 clay in the Milwaukee section may be referable to the Bowmanville low water 

 stage. Calvin 1511 states that in 1876 a complete skeleton ofan elephant was 

 found near Adel, Dallas Co., in peat which partly filled a 'kettle' in the Wis- 

 consin drift. 



A few years ago Mr. F. M. Woodruff, of the Chicago Academy of Sciences, 

 secured a number of postglacial mollusks from marl deposits near Waukesha. 

 This locality is in the northwestern part of Waukesha County, and is well 

 within the area of the Wisconsin ice sheet. The body of water in which the 

 mollusks lived was one of the many small lakes left by the retiring lobes of the 

 Lake Michigan Glacier (Delavan lobe). It has not been possible to correlate 

 this marl bed with any one of the glacial stages of Lake Chicago. Mr. Wood- 

 ruff reports the shells as very abundant. The following species have been 

 noted : 



Amnlcola walkeri Planorbis campanulatus 

 Physa walkeri. Some scalariform " antrosus 



Physa warreniana " parvus 



Galba narshotakensis " exacuous 



Alden 156 records several mammals as occurring in postglacial deposits in 

 southeastern Wisconsin. They may have been buried during any of the lake 

 stages and a few may belong to recent time. 



Cenus canadensis. Antler. 



Wauwatosa at depth of 4 feet. 

 Mammut americanum. Tusk and other bones. 



Racine County, Dover township, in well. 

 Elephas primigenius. Bones and upper jaw. 



Milwaukee at depth of 13 feet. 



5S * Smith Contr. to Knowledge, XV, Act. 2. 



ub Professional Paper 106, U. S. G. S., pp. 346-347. 



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