Columnaria thomii Han, 1857 
ANTHOZOA Columnaria thomii 
Hall, 1857. 
No original diagnosis 
OBSERVATIONS 
There is no original description nor is the locality of the specimen where found given. 
The species was based on a single specimen of which a part has been sawed off since the 
original figures were made. 
Columnaria Thomii belongs to the genus Cyathophylloides Dybowski, 1873, and appears be 
more nearly related to the Estland C. fasciculus Kutorga, than to the Canadian Diphyphyllum 
Stokesii Edw. et Haime. The former differs from both these species in having smaller 
corallites each of which has about 22 primary septa. 
Cyathophylloides appears to be a characteristic coral of the upper formations of the Lower 
Silurian of Estland and Livland. The genus has not hitherto been recognized in America 
but there seems to be no doubt that C. Thomii and Diphyphyllum Stokesi (1897. — Whiteaves, 
Geol. Surv. Canada, Pal. Fos., vol. I, part. I, p. 152. PI. XVII, fig. 5, 52, sb) are species 
of Cyathophylloides. Diphyphyllum Stokesii occurs in Manitoba in association with species that 
indicate the highest Lower Silurian of Richmond. 
Recently, the U. S. Geological Survey has collected this species in abundance about 
El Paso, Texas, associated with Halysites, Hebertella insculpta, Rhynchotrema capax, etc., 
indicating the Richmond formation. 
1903. Ch. D. Walcoit. 
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