Table 8 (concluded) 



Species 



Strophitus undulatus 



Simpsoniconcha aiabigua 



Obliquar-?a reflexa 



Qbovaria olivaria 



Actinonaias ligamentina 



Actlnonaias ellipsif ormis 



Plagiola lineolata 



Truncilla truncata 



Truncilla donaciformis 



Leptodea fragilis 



Leptodea leptodon 



Proptera alata 



Proptera cap ax 



Proptera laevlssima 



Carunculina parva 



Ligumla recta 



Ligumia subrostrata 



Lampsilis anodontoides f . anodontoides 



Lampsilis anodontoides f . fallaciosa 



Lampsilis radiata luteola 



Lampsilis ventricosa 



Lampsilis orbiculata f . orbiculata 



Lampsilis orbiculata f . higginsii 



1906 

 x 



1931 



1975-76 



Number of species collected in Mississippi River 

 in 1906, but not in 1975-76 



Number of species collected in Mississippi River 

 in 1931, but not in 1975-76 



Number of species collected in Pools 24, 

 in 1931, but not in 1975-76 



25. and 26 



Sheet 2 of 2 



51 



