86 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
Galba 
II. STRATIGRAPHICAL TABLE OF EXTINCT AMERICAN LYMNAEFAS. 
era: 
Mesozoic 
( 
| 
4 
| 
( 
( 

Tertiary 
Cenozoic. 
wc NA 
Quaternary 
oe eth 
THE CHICAGO ACADEMY OF SCIENCES. 
similis (Meek). Middle Eocene. 
diaphana (E. & S.). Oligocene. 
nebrascensis (E. & S.). Oligocene. 
meckiana (EF. & S.). Oligocene. 
shumardi (Meek). Oligocene. 
florissantica (Cockerell). Oligocene. 
contracosta (Cooper). Pliocene. 
alamosensis (Arnold). Pliocene. 
bonnevillensis (Call). Pliocene. 
bakeri (Walker). Pliocene. 
nashotahensis (Baker). Pliocene. 
accelerata (White). Comanchean. 
Subgenus POLYRHYTIS Meek. 
kingit Meek. Lower Pliocene. 
Period. Formation. Species. 
Comanchean or Atlantosaurus. ( ativuncula White. 
Lower Cretaceous. (Morrison; Como.) 4 consortis White. 
Rare Ree accelerata White. 
Cretaceous. nitidula Meek. 
; ( tenuicosta M. & H. 
Cretaceous. Laramie. | 
Fort Union. 
( Lower Eocene. [ 
4 
| | Wasatch. 
| Middle Eocene. Bridger. 
( White River. 
| 
Oligocene. 4 

| 
(Florissant. 
Middle Miocene. Mascall. 
Lower Pliocene. Humboldt. 

[ | (Merced series.) 
Upper Pliocene. 4 Fernando. 
Bonneville beds. 
Anticosti Marl beds. 
Pleistocene. Michigan Marl beds. 
Wisconsin Marl beds. 
( Contracosta Lake bed. 
4 t. whiteavesi Baker. 
Lcompactilis White. 
tenuicosta M. & H. 
tenuicosta M. & H. 
minuscula White. 
ee Meek. 
similis Meek. 
(diaphana E. & S. 
| nebrascensis E. & S. 
4 meekiana E. & S. 
shumardi Meek. 
scudderit Ckll. 
4 sieverti CkIl. 
| florissantica Ckll. 
stearnsi Hannibal. 
kingi Meek. 
contracosta Cooper. 
alamosensis Arnold. 
bonnevillensis Call. 
anticostiana Dall. 
bakerit Walker. 
nashotahensis Baker. 

| 
| 
