6 LAND AND FRESH WATER MOLLUSKS 



TABLE I, DISTRIBUTION OF FRESH WATER SHELLS NORTH 

 OF LATITUDE 49 , ACCORDING TO THE DRAINAGE 



systems now existing. — Continued. 



Name of Specie*. 



Margaritana var. falcata , 



Unio complanatus , 



Quadrula plicata 



Quadrula undulata , 



Quadrula heros 



Quadrula lachrymosa .... 



Quadrula rubiginosa , 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphser 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer: 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



Sphaer 



ium simile 



ium striatinum , 



ium solidulum 



ium stramineum , 



ium rhomboideum 



ium walkeri 



ium fabale ..... 



ium occidentale 



ium patella , 



ium emarginatum ..... 



ium tumidum , 



ium spokani , 



ium raymondi 



ium partumeium 



ium jayanum 



ium tenue 



ium transversum 



ium truncatum 



ium lenticulum 



Corneocyelas virginica 



Corneocyclas idahoensis 



Corneocyelas scutellata 



Corneocyclas aequilateralis . 



Corneocyclas compressa 



Corneocyclas variabilis 



Corneocyclas abdita 



Corneocyclas ventricosa .... 



Corneocyclas rotundata 



Corneocyclas steenbuchi.... 

 Corneocyclas occidentalis... 

 Corneocyclas ultramontana. 



Corneocyclas arctica 



Corneocyclas nivalis 



Corneocyclas glacialis 



Corneocyclas pulchella 



Corneocyclas henslowana ... 



o* 



