104 HENRY SHALER WILLIAMS 
Dalmanella carinata Hall is described as coming from the localities 
Painted-Post, Chemung, and Jasper’ under the name Orthis carinata. 
But in the final description of the species? it is referred to Painted- 
Post alone. The statement is made that it “has not been obtained 
from any other locality,” and we are told that in many of its charac- 
ters this species assimilates with Orthis tioga and one of the localities 
from which Orthis tioga is cited is Chemung Narrows.. Hence we 
may infer that the species selected as typical of the Chemung Nar- 
rows section is Orthis tioga, and although O. carinata has been dis- 
covered there, Hall evidently changed his opinion as to the Chemung 
Narrows form while the final report on Paleontology was being 
prepared. 
Dalmanella tioga Hall.—This species was originally described and 
figured by Hall+ under the name Orthis interlineata Sowerby. It 
was later described by him under the name Orthis tioga.s Still later 
it was placed by Hall and Clarke in the genus Schizophoria King.° 
And in the year 1905 the characters of the species were shown by Wil- 
liams to be those of the genus Dalmanella, not Schizophoria.”?_ It was 
pointed out by Williams that in Schizophoria the pedicel valve is 
resupinate, and, in the upper Devonian forms, presents a distinct 
sulcus along the center of that valve. The pedicel valve of Dal- 
manella on the other hand is distinctly elevated into a fold or narrow 
ridge, and in that genus the valve with the sulcus is the brachial 
valve, which is always convex in Schizophoria. There are other inter- 
nal characters to separate the two genera, but the above external 
characters are sufficiently large and conspicuous to be detected in 
the field and furnish the evidence of the genus Dalmanella, by which 
presence of the Chemung fauna may be established for this province. 
The genus was prominent in the Ordovician and Silurian and appears 
conspicuously in the lower Helderberg. ‘The only report of the genus 
t Geol. N. Y. Rep. Fourth Dist. (1843), p. 267, Fig. 1. 
2 Paleontology of New York, Vol. IV (1867), p. 58, Pl. 8, Fig. 30-32. 
3 Loc. cit., p. 59. 
4Geol. N. Y. Rept. Fourth Dist. (1843), p. 268, Figs. 3, 4. 
5 Paleontology of New York, Vol. IV (1867), p. 59, Pl. VIII, Figs. 20-29, 
6 Op. cit., Vol. VIII, Pt. 1, 1892, pp. 212, 226, Pl. VI, Figs. 17, 18. 
7U. S. Geol. Sur. Bull. 244 (1905), p. 86. 
ee 
