PAPERS OX GEOLOGY AND GEOGRAPHY 417 



The peat deposits along Sag Creek represent a later 

 time than the marl fossils at Joliet, and are probably to 

 be classed with the deposits of the Englewood stage or 

 the latter part of the Hammond stage. (Baker, Life of 

 Pleistocene, pp. 57, 86, 88, 94.) The^life of the two sta- 

 tions are practically identical as far as the critical species 

 are concerned. 



Mr. D. J. Fisher, of the Illinois State Geological Snr- 

 vey, has submitted for study several collections of Pleis- 

 tocene Mollnsca obtained from various places in the Joliet 

 Quadrangle. These are listed below with notes on the 

 species. 



STATIOX xo. 1 



Localitv: Above old qnarrv in the SE part of Joliet, 

 N. W. I4.' of S. E. I4, Sec. 15, T. 35 X., E. 10 E. 



Material : Calcareous marl. 



Stratigraphic horizon: TTabash; Possibly the Bow- 

 manville Low Water Stage. 



MOLLUSCAN LITE 

 LAXD GASTROPODS 



Pyramid id a sol it aria, common. 

 Polygyra thyroides, rare. 

 Polygyra clausa, rare. 

 Strohilops affinis, rare.* 

 Zonitoides arhorea, rare.* 

 Succinea retiisa, rare. 



AQUATIC GASTROPODS 



Valvata tricarinafa, not common. 

 V. tricarinafa perconfusa, rare. 

 Amnicola leiglitoni, not common. 

 Amnicola lustrica gelida, rare. 



AQUATIC pul:monates 



Planorhis trivolvis, rare. 



Planorhis antrosus striatus, common. 



Planorhis campanulatus ferrissi, not common. 



Planorhis aJtissimus, rare. 



Planorhis deflectus, rare. 



