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PALEONTOLOGY OF NEW YORK. 
Subgenus CCELOSPIRA, Hall. 1863. 
PLATE LIII. 
1839. Atrypa, Sowerby. Murchison’s Silurian System, p. 637, pi. xx, fig-. 7. 
1841. Atrypa, Conrad. Geol. Surv. N. Y.; Ann. Kept. Palseont. Dept., p. 54. 
1843. Atrypa, Hall. Geology of N. Y. ; Kept. Fourth Dist., p. 71, fig. 4. 
1852. Atrypa, Hall. Palteontology of N. Y., vol. ii, pp. 74, 75, pi. xxiii, figs. 9-11. 
1855. Hemithyris, McCoy. Bi-itish Paljeozoic Fossils, p. 201. 
1857. Leptoccelia, Hall. Tenth Ann. Kept. N. Y. State Cab. Nat. Hist., p. 107. 
1859. Leptoccelia, Hall. Palaeontology of N. Y., vol. iii, p. 245, pi. xxxviii, figs. 1-7. 
1863. Coelospira, Hall. Sixteenth Ann. Kept. N. Y. State Cab. Nat. Hist., p. 60. 
1866. Leptoccelia, Billings. Catalogue of Silurian Fossils of Anticosti, p. 48. 
1866. Atrypa, Davidson. British Silurian Brachiopoda, p. 136, pi. xiii, figs. 23-30. 
1867. Cceloepira, Leptoccelia, Hall. Palaeontology of N. Y., vol. iv, pp. 328-330 (fig. 1), 365, pi. lii, 
figs. 13-19; pi. Ivii, figs. 30-39. 
1884. Leptoccelia, Davidson. General Summary, p. 424. 
The term Ccelospira was proposed in the Sixteenth Annual Report of the 
New York State Cabinet of Natural History (p. 60) for the Lower Helderberg 
species C. concava, Hall, which originally had been referred* to the genus Lep¬ 
toccelia. The reason for the separation was expressed in a figure of the bra¬ 
chial apparatus accompanying the first use of this name. The spirals were 
represented as loosely coiled and almost in the same plane, the apices being 
very slightly elevated and directed outward; the loop posteriorly situated, 
broad and continuous, very similar to that of Zygospira. The Leptomlia concava 
is a small piano-, or subconcavo-convex shell, covered with rather numerous 
simple or bifurcating plications. The pedicle-valve has distant teeth arising 
from the lateral cardinal slopes, and in front of the umbonal cavity are a pair 
of rather deep oval diductor scars, which embrace the anterior extremities of 
two narrow, less excavated adductors. These are separated by a narrow, more 
or less conspicuously developed median ridge as in Terebratula venusta and 
T. lepida. 
The cardinal process has the same structure as in Anoplotheca, consisting of 
a central portion curved backward to, or slightly beyond the hinge, and faintly 
bilobed on its posterior extremity. The crural bases are consolidated with the 
central process and are continuous with the socket walls. There is a stout 
* PaliEontology of New York, vol. iii, p. 245, 1859 ; and Tenth Kept, N. Y. State Cabinet, p. 107, 1857. 
