138 LIFE OF THE PLEISTOCENE 



Sphaerium occidentale Planorbis trivolvis 



Pisidium compression Segmenlina armigera 



" scutellatum Galba caperata 



" variabile " humilis modicella 



Valvata tricarinata " palustris 



Goniobasis livescens Succinea avara 

 Amnicola limosa " retusa 



" walkeri Vertigo species 



Physa elliptica Zonitoides minuscula 



Planorbis hirsuhis Polygyra monodon 



" parvus Bifidaria pentodon 



(2) Ditch, 12-18 inches deep, on the line between sections 9 and 10, T. 

 13 N, R. 5 E., south of the quarter post. The deposit is clay containing small 

 pebbles. Specimens were also seen in the same section farther east. During 

 the high water of the spring of 1904, this region was entirely flooded. The 

 area is on the border of the prairie region. The following fauna was obtained 

 from this deposit: 



Sphaerium simile Planorbis antrosus 

 Pisidium adamsi ajfine " campanulatus 



" compressum " defiectus 



" medianum " exacuous 



" sar genii " hirsutus 



" scutallatum " parvus 



" splendididum " trivolvis 



Valvata tricarinata Segmenlina armigera 



Goniobasis livescens Galba caperata 

 Campeloma decisa " obrussa{ = desidiosa) 



Amnicola limosa " reflexa 



" walkeri Succinea retusa 



" lustrica Polygyra monodon 

 Physa heterostropha " midtilineata 



" gyrina Jiildrethiana 



(3) Muck underlying clay in a ditch on the west line of northwest quarter 

 section 31, Merritt Township. The elevation is 586 to 588 feet above tide. 

 Sixteen species of mollusks have been identified. 



Sphaerium flavum Physa gyrina hildrethiana 



" simile Planorbis antrosus 

 " occidentale " campanulatus 



Pisidium compressum " defiectus 



" scutellatum " trivolvis 



Valvata tricarinata Galba reflexa 



Goniobasis livescens Lymnaea stagnalis appressa 



Campeloma intcgra Succinea retusa 



Mr. Frank B. Taylor (in a letter) reports four species from the Nipissing 

 beach, in gravels, a little below the top, at Cheboygan. 



