54 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
Dr. 7 I is on the east side of Bald Hill, Caroline, Tompkins 
County, New York. Both of these localities are of typical sections 
of the Dalmanella danbyi zone at the base of the Cayuta member of 
the Chemung formation. ; 
ORTHIS TIOGA Hall. 
Among the original figures illustrating Hall’s species Orthis tioga 4 
‘two distinct forms are recognized. Figs. 26 and 21 on Plate VIII 
are of form alpha, figs. 20, 22, and 29, are form beta, as those terms 
are used above in describing Dalmanella leonensis. ‘The form gamma 
is not represented among the figures of this species. Subquadrate 
specimens in which the hinge line is long and the cardinal angles 
abrupt is represented in figs. 25 and 23; this is form delta. Orthis 
carmata Hall is an extreme of the modification expressed by form 
delta, and has been called forms epsilon and zeta.” 
In order to discuss the geological and geographical relationship 
of these several forms specific names are required to represent them. 
The form beta, first figured by the author, is adopted in his original 
description as the typical form of Orthis tioga. Figs. 20 and 23 
on Hall’s Plate VITI, are typical of that description. That form was 
referred to Sowerby’s species O. interlineata by Hall in 1843, and 
the statement was made that “the figures of Sowerby correspond 
better with the fossils than those of Mr. Phillips. The casts, how- 
ever, fig. 3 above, and 106a of the latter, very closely resemble each 
other, and there can be no doubt of the identity of the fossils.” ¢ 
More careful study of the New York forms led Hall to refer these 
broadly elliptical forms (form beta) to the species Orthis tioga, but 
with them were associated others of the form which Phillips regarded 
as specifically different and to which he gave the name Ovthis paral- 
lela, placing it in his group of * orbicular orthides ” instead of * ellip- 
liptical orthides ” in which O. tnterlineata was included. 
The second form alpha is represented among the figures of Hall’s 
species O. tioga by figs. 8 and 8.“ To the small representatives of 
form alpha the names D. leonensis and D. danbyi are here given. 
For the large species of form alpha, such as Hall included in the. 
species Orthis tioga, the name Dalmanella elmira is proposed. 
WBA ING Woy JOG JUS, 1s HO jail, Waneg, TS, AO) 
b See p. 46. 
€ Geol. N. Y., 4th Dist., 1843, p. 268. 
@ Hall, Pal. N. ¥., LV. Brachiopodes, 1867, pl. viii. 
