BRACHIOPODA. 
15 
(1) 
1849. 
(1) 
1852. 
(1) 
1856. 
(2a) 
1856. 
G) 
1857. 
(2a) 
1857. 
(26) 
1857. 
(1) 
1858. 
(2a) 
1858. 
(1) 
1859. 
(26) 
1859. 
(1) 
1860. 
(26) 
1860. 
(1) 
1860. 
(1) 
1861. 
(2a) 
1861. 
(2a) 
1862. 
(1) 
1863. 
(1) 
1863. 
(2a) 
1863. 
(2a; 
1866. 
(1) 
1867. 
(2a) 
1867. 
(26) 
1867. 
(1) 
1868. 
(1) 
1871. 
(16) 
1874. 
(1) 
1874. 
(26) 
1876. 
(26) 
1877. 
(1) 
1878. 
(1) 
1882. 
(2a) 
1882. 
(1) 
1883. 
(1) 
1884. 
(2a) 
1884. 
(1) 
1889. 
(26) 
1889. 
(2a) 
1889. 
(2a) 
1891. 
Spirifer, Hall. American Journal of Science, vol. xx, p. 228. 
Spirifet’, Hall. Palaeontology of N. Y., vol. ii, p. 261, pi. liv, fig. 2. 
Spinfer, Billings. Canadian Naturalist and Geologist, vol. i, p. 137, pi. ii, fig. 7. 
Spirifera, Billings. Canadian Naturalist and Geologist, vol. i, ]>. 474, pi. vii, figs. 9, 10. 
Spirife)', Hall. Tenth Kept. N. Y. State Cab. Nat. Hist., p. .67, figs. 1-5. 
Spinfer, Hall. Tenth Ann. Kept. N. Y. State Cab. Nat. Hist., pp. 130, 131. 
Spirifer, Hall. Tenth Ann. Rejit. N. Y. State Cab. Nat. Hist , pp. 62, 63, 134. 
Delthyris, Rogers. Geology of Pennsylvania, vol. ii, p. 825, fig. 643. 
Spinfer, Hall. Geol. Survey of Iowa, p. 507, pi. iv, figs. 6 h, c, cl; p. 501, pi. iv, figs. 3a-c. 
Spinfer, Hall. Palaeontology of N. Y., vol. iii, p. 201, pi. xxvi, figs. 1, 2. 
Spirifei-, Hall. Palaeontology of N. Y., vol. iii, p. 419, pi. xcvi, figs. 7 a-f; p. 421, pi. xcvi, 
figs. 9 a-g. 
Spirife^', Hall. Thirteenth Rept. N. Y. State Cab. Nat. Hist., p. 94. 
Spirifer, Meek. Proc. Acad. Nat. Sci. Philadelphia, vol. iv, p. 308. 
Spinfer, Hall. Canadian Natui-alist and Geologist, vol. v, p. 145. 
Spirifera, Billings. Canadian Journal, vol. vi, p. 258, figs. 71-73. 
Spirifera, Billings. Canadian Journal, vol. vi, pji. 254, 255, figs. 59-64. 
Spirife)’, A. Winchell. Proc. Acad. Nat. Sci. Philadelphia, vol. xiv, ii. 405. 
Spirifera, Billings. Proc. Portland Soc. Nat. Hist., vol. i, p. 117, pi. iii, fig. 17. 
Spirifera, Billings. Geology of Canada, p. 372, fig. 392; jn 386, fig. 423; p. 957, fig. 455. 
Spirifera, Billings. Geology of Canada, p. 960, fig. 467; p. 386, fig. 424 a-d. 
Spirifecu, A. Winchell. Rei^t. Lower Peninsula of Michigan, p. 93. 
Spirifera, Hall. Palaeontology of N. Y., vol. iv, pp. 192, 221, 222, 240, pi. xxvii, figs. 30-34 ; 
pi. XXX, figs. 1-9 ; pi. XXXV. figs. 10-23 ; pi. xl, figs. 1-13. 
Spirifera, Hall. Palaeontology of N. Y., vol. iv, p. 205, pi. xxxi, figs. 1-4; p. 207, pi. xxxi, 
figs. 14-19; p. 208, pi. xxxi, figs. 9, 10; p. 216, pi. xxxiv, figs. 1-32. 
Spirifera, Hall. Palaeontology of N. Y., vol. iv, p. 190, pi. xxvii, figs. 18-28. 
Spirifera, Meek and Worthen. Geological Survey of Illinois, vol. iii, p. 384, pi. vii, fig. 9. 
Spirifera, Nicholson. Paleontology of Province of Ontario, p. 82. 
Spirifera, Nicholson. Paleontology of Province of Ontario, p. 80. 
Spirife^-a, Billings. Paleozoic Fossils, vol. ii, p. 47, pi. iii a, fig. 5. 
Spirifer, Meek. Simpson’s Rept. Expl. Great Basin Utah, p. 346, pi. i, fig. 1, 
Spirifer, Meek. King’s Rept. Expl. Fortieth Parallel, vol. iv, p. 41, pi. iii, fig. 3. 
Spirifera, Dawson. Acadian Geology, third ed., p. 576. 
Spirifera?, Whitfield. Geology of Wisconsin, vol. iv, p. 332, pi. xxv, figs. 23, 24. 
Spinfera, Whitfield. Geology of Wisconsin, vol. iv, p 328, pi. xxv, figs. 27, 28. 
Spirifera, Hall. Second Report N. Y. State Geologist, pi. lix, figs. 9, 27-34; pi. lx, 
figs. 1-18. 
Spirifera, Walcott. Monogr. U. S. Geol. Survey, vol. viii, p. 135, pi. iv, fig. 2; pi. xiv, 
fig. 12. 
Spirifera, Walcott. Paleontology Eureka Dist., pp. 136, 217, pi. vii, fig. 8. 
Spirifet'a, Nettelroth. Kentucky Fossil Shells, pp. 128, 132, pi. xvii, figs. 38-42 ; pi. xxxi, 
fig. 13. 
Spirifera, Nettelroth. Kentucky Fossil Shells, p. 112, pi. xii, tigs. 1-4. 
Spirifera, Nettelroth. Kentucky Fossil Shells, p. 134, pi. x, tigs. 11-20, 23-25 ; fi- 109, 
pi. X, figs. 1-5, 31-34, 36-39 ; p. 121, pi. x, figs. 21, 22, 26-30, 35, 40; p. 108, 
pi. xii, figs. 14, 15 ; p. 132, pi. xiii, figs. 36, 38; p. 126, jfi. xxxi, figs. 10, 11. 
Spirifera, Whiteaves. Contributions to Canadian Paleontology, vol. i, p. 223. 
Radially plicated; surface covered with numerous concentric lamellge. In 
Silurian species the fold and sinus are non-plicate; the later forms usually 
