236 
PALEONTOLOGY OF NEW YORK. 
Genus PENTAMERUS, Sowbrby. 1813. 
PLATES LXVII, LXVIII, LXIX, LXX. 
1813. Pentamerus, J. Sowbrby. Mineral Conchology, vol. i, p. 76, pi. xxviii. 
1839. Penfanierus, J. db C. Sowbrby. Silurian System, pi. xix, figs. 9, 10. 
1843. Pentameruft, Hall. Geology of New York; Kept. Fourth Dist., p. 70, figs. 1-5. 
1845. Pentamerus, de Vbrneuil. Geologic de la Russie, p. 119, pi. viii, figs. la-c. 
1852. Pentamerus, Hall. Paleontology of New York, vol. ii, p. 79, pi. xxv, figs. la~m; pi. xxvi, 
figs. 1 a-d; p. 103, pi. xxxi, fig. 1. 
1854. Pentamerus, Eiciiwald. Bull. Soc. Imp. Natural. Moscou, pt. 1, p. 91. 
1854. Pentamerus, F. SciiMroT. Neueste Unteisuch. ueher Brachiopoden, p. 213. 
1859. PentamerxLS, Eichwald. Lethea rossica, vol. i, p. 788, pi. xxxiv, fig. 23. 
1861. Pentamerus, McCuesnby. New Paleozoic Fossils, p. 85. 
1863. Pentamerus, Billings. Geology of Canada, p. 316, fig. 326. 
1866. Pentamerus, Billings. Catalogue Silur. Fossils Anticosti, p. 45. 
1867. Pentamerihs, Davidson. British Silurian Brachiopoda, p. 151, p). xviii, figs. 1-12; pi. xix, figs. 1, 2. 
1867. Pentamerus, Hall. Paleontology of New York, vol. iv, pp. 369-374. 
1868. Pentamerus, McChbsney. Trans. Chicago Acad. Sci., vol. i, pi. ix, fig. 1. 
1872. Pentamerus, Hall and Whitfield. Twenly-fouilh Ann. Kept. N. Y. State Mus. Nat. Hist., 
p. 183. 
1875. Pentamerus, Hall and Whitfield. Twenty-seventh Ann. Kept. N. Y. State Mus. Nat. Hist., 
pi. X, figs. 13, 14. 
1875. Pentamerus, Hall and Whitfield. Paleontology of Ohio, vol. ii, pp. 137, 139, pi. vii, tigs. 9-11. 
1882. Pentamerus, WHiTifiBLD. Annals N. Y. Acad. Science, vol. ii, p. 195. 
1882. Pentamerus, Whitfield. Geology of Wisconsin, vol. iv, pp. 288, 291, jd. xvii, figs. 3-9. 
1889. Pentamerus, Nbttelroth. Kentucky Fossil Shells, pp. 60-62, pi. xxix, figs. 23, 24 ; jd. xxx, 
figs. 2-4. 
1889. Pentamerus, Foerste. Pi'oc. Boston Society Nat. Hist., vol. xxiv, p. 324, pi. v, figs. 17, 18. 
1890. Pentamerus, Whitfield. Annals N. Y. Acad. Sci., vol. v, p. 513, pi. v, figs. 11-22. 
1890. Pentamerus, Gagel. Die Brachioji. der camb. und silur. Geschiebe im Diluvium der Provinzen 
Ost- und Westpreussen, p. 53, pi. iv, fig. 1. 
Since it seems necessary to restrict the term Conchidium to those pentame- 
roids embraced by de Verneuil in his division “ plisses, sans sinus,” it becomes 
desirable to apply the designation Pentamerus to the second division of those 
shells, the “ lisses, sans sinus.” This use of Sowerby’s term is in precise 
accordance with recognized rules of nomenclature. The first species cited by 
SowERBY, and that which has been generally regarded as typical of the genus 
by authors who have preferred this term to the earlier designation of Linne, 
is P. Knighti, a plicated shell, which belongs to Conchidium.* The second of 
Sowerby’s typical examples, and that to which must be accorded his generic 
* The P. Aylesfordi, Sowerby, cited in the “ Mineral Conchology ” as another of the typical species of 
Pentamerds, was subsequently regarded by that author as a synonym for P. KnigMi (Silurian System, 
p. 615, 1839), and the name has consequently fallen into disuse. 
