1 6 The American Geologist. Jniy, l89^ 
As to whether Osage or Augusta shall stand as a term in 
American geology can only be settled by impartial judges. 
Osage clearly has priority and has been adopted by Dana* 
and by Scottt in the two latest text books of the science. 
The name was also adopted by the late geological survey of 
Arkansas. The name Augusta has been used only by the 
geological surveys of Iowa and Missouri, with which Mr. 
Keyes has been personally associated. 
ON THE DEVELOPMENT OF TETRADIUM 
CELLULOSUM HALL, SP. 
By R. RuEDEMANN, Ph. D., Dolgcville, N. Y. 
(Plato V.) 
The writer found in the Birdseye limestone (lower Tren- 
ton) of Ingharm's Mills, Herkimer county, N. Y., a layer of 
limestone (i^^° thick), which consists largely of a fossil de- 
scribed by Prof. James Hall^ as Phytopsis cellidosiim. The oc- 
currence of the fossils in the neighborhood of banks with 
carbonaceous ''birdseyes" (described as Phytopsis tubulosnni 
in the same paper) and the apparent cellular structure in 
transverse and longitudinal sections, on account of the sep- 
tal partitions and tabulae, invited the above identification at 
a time when the genus Tetradium, though already created 
by Dana, was not yet well known; no species of it having 
been described. 
The material from Ingharm's Mills is so well preserved 
that it at once shows that the fossil belongs to the little 
known and interesting genus Tetraditim, Dana, of the tabu- 
late corals and, therefore, should be identified as Tctradium 
cellulosivn Hall, sp., which name it also bears in the catalogue 
of Prof. Hall's collection. A figure given b)' Prof. Hall well 
illustrates that this species does not grow in compact masses 
like most other species of Tctradium, but possesses a cespi- 
tose, dichotomously branching corallum. This mode of 
growth, however, gives an excellent opportunit}^ to stud)' the 
*Man. Geol., 4th ed., pp. 634 and 637. 
flntro. to Geol., p. 409. 
JNat. Hist, of New York, part VI, Pali^ontology, vol. I, p. 39, 1847. 
