142 



BRITISH SILURIAN BRACHIOPODA. 



Family— RHYNCHONELLID^. 



Genus — Pentamerus, Soicerby, August, 1813. 



For the description of this genus, see the " General Introduction," ' Monograph of 

 British Fossil Brachiopoda,' vol. i. 



Pentamerus Knightii, Sow. PI. XVI, figs. 1—3; PI. XVII, figs. 1—10; PI. XIX, 

 fig. 3. 



Pentameeus Knightii, Sow. Min. Conch., vol. i, p. 73, pi. xxviii, August 1st, 

 1813. 



— Aylesfordii, (Sow;. Ibid., pi. xxix, 1813. 



— Knightii, Id. Sil. Syst., p. 615, pi. vi, fig. 8, a, b, c, 1839. 



— — F. A. Roemer. Verstein. Harzgebirges, pi. v, fig. 16, 1843. 



— — ? Barrande. Naturwiss. Abband., vol. i, p. 107, pi. xxi, fig. 



3, 1847. 



— — Dav. Bull. Soc. Ge'ol. France, 2nd ser., vol. v, p. 333, 1848. 



— — Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 292, 



1848. 



_ _ Bronn. Index Pal., p. 944, 1848. 



— — UOrb. Prodrome, vol. i, p. 41, 1849. 



— — F. A. Roemer. Beitr. Geol. Kenntniss d. nord-westl. Harzge- 



birges, p. 59, 1850. 



— — 3PCoi/. Brit. Pal. Foss., p. 209, 1852. 



— — Gruenewalt. Verst. Silurisch. Kalkstein von Bogosslowsk ; 



Mem. Sav. Etrang., vol. vii, p. 26, pi. iv, fig. 15, 1854. 



— — S. P. Woodward. Manual of the MoUusca, p. 228, fig. 143 ; 



pi. XV, fig. 22, 1854. 

 _ _ Morris. Cat. of Brit. Foss., p. 142, 1854. 



— — De Verneuil. Geol. of Russia, vol. ii, pi. vii, fig. 1, 1845. 

 _ _ C. Giebel. Silur. Fauna d. Unter-harzes, p. 46, 1858. 



— — Salter. Siluria, 2nd edit., pi. xxi, fig. 10 ; and var. ^?//e«/brrf«, 



fig. 11, 1859. 



— — Billings. Canad. Journ., p. 59, fig. 90, 1861. 



— — Salter. Explanat. Sheets, 160, &c., Geol. Surv. Ireland, p. 13, 



1863. 



Sj)C'c. Char. Shell impunctate; ovate, or longitudinally oval, sometimes obscurely 

 pentagonal, and as wide as long ; more rarely transversely oval and wider than long ; 

 the young form at times trigonal. Ventral valve ventricose or more convex than the 

 opposite one, evenly rounded or flattened along the middle ; beak large and very much 



