8 THE NAUTILUS. 



Family Margaritanida 

 Margaritana margaritifera (Linn^) 



Family Sphaeriida. 



Spharium striatinum (La- Pisidium variabile Prime. 



marck) Pisidium covipressum Prime. 



Sphcerium vermontanum Pisidium compressum Icevigatum 



Prime. Sterki. 



Musculium, securis (Prime) Pisidium henslowanum 

 Muscidium rosaceum (Prime) (Sheppard) 



Pisidium ferrugineum Prime. Pisidium, 4 undet. spp. 

 Pisidium seqidlaterale Prime. 



Class Gastropoda. 

 Family Viviparidse. 

 Vivipara contectoides W. G. Campeloma decisum (Say) 

 Binney. Campeloma integrum (DeKay) 



Family Amnicolidae. 

 Amnicola limosa (Say) Somatogyrus subglobosus (Say) 



Amnicola lustrica Pilsbry Gillia altilis (Say) 



Amnicola lustrica Pilsbry, Bythinia tentaculata (Linn6) 

 variety 



Family Valvatidx. 

 Valvata tricarinata (Say) Valvata bicarinata normalis 



Walker 



Family Pleuroceridae. 

 Goniobasis livescens (Menke) 



Family Physidse. 

 Physa ancillaria warreniana Physa integra Haldeman. 

 (Lea) Physa gyrina Say 



Family Ancylidae. 

 Ancylus tardus Say Ancylus parallelus Haldeman. 



Ancylus fuscus C. B. Adams. 



