Ce 
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ORIGIN OF THE CHOUTEAU FAUNA 287 
Edmondia De Koninck is a form of doubtful affinities and 
was described from Carboniferous specimens. Although it 
occurs in New York it is there a Chemung form, and on the 
theory that the Chouteau is later than the Chemung, there is no 
difficulty in supposing a common origin for its species. For if 
we apply the theory that these species came from the eastern 
Hamilton, we have the same reason for so accounting for the 
origin of the Admondias of European Carboniferous, which is 
evidently absurd. 
Pterinea Goldf. is a genus of wide range, from the Silurian to 
the Carboniferous, and its absence from a particular list of 
species in Devonian time cannot be taken as evidence that it 
was not then living under appropriate conditions in the same 
seas. 
Sphenotus, until distinguished by Hall, in 1895, was recorded 
under the name Sangwinolites McCoy, or Cypricardia Lam., or 
Cypricardima Hall. The genus under these names was known 
in the European Devonian, and one does not need to look to the 
eastern New York Devonian for its origin in the Chouteau. 
Straparollus Montf. is reported under that name in Europe 
from the Silurian to the Triassic, and it is an ancient type and 
should not as a genus be used as indication of local origin of 
any fauna so late as the Carboniferous era. 
All the other genera of Lamellibranchiata and Gastropoda, 
as well as all the Brachiopoda named in the list were known in 
the western or European Devonian fauna. 
The crinoids mentioned, if not included in lists of European 
Devonian species may be there omitted because they did not 
appear until the Carboniferous time, in which case we have to 
account for their presence there as well as in America, or, as in 
the case of Platycrinus and Scaphiocrinus, they are only rarely 
found below the Carboniferous, and have to be accounted for 
as newly evolved genera rather than as descendants of species 
of the same genus in lower rocks. 
The case of Michelinia must have been an oversight, for the 
genus is reported under that name from the Devonian of Europe, 
