STRINGOCEPHALUS. ] 1 



Genus — Stringocephalus, Defrance. 

 Stringocephalus Burtini, Defrance. PI. I, figs. 18 — 2.2; PI. II, figs. 1 — 11. 



Strygocephalus Burtini, Defrance. Die. des Sciences Naturelles, vol. li, p, 102, et Atlas r 



pi. lxxv, figs. 1, 1", 1827. 

 Terebratula porrecta, Sow. Min. Con., pi. 5/6, fig. 1, Nov., 1827. 

 Strigocephalus Burtini, Blainville. Malacologie et Conchyliologie, p. 511, t. liii. 

 Terebratula strigocephalus, V. Btich. Ueber Terebrateln, p. 117, 1834. 

 Strigocephalus giganteus, Sowerby (Terebratula gigantea, Sow., Eucyc. Metropl.), 



Trans. Geol. Soc. of London, vol. v, 2nd series, pi. Ivi, 



figs. 10, 11, 1837-39. 

 Strygocephalus Burtini, V Arcldac et De Verneuil. Description of the Fossils in the 



Older Deposits of tlic Rhenish Provinces ; Trans. Geol. Soc. of 

 London, 2nd series, vol. vi, p. 393, 1840. 



— dorsatus, Be Vern. (Strygocephalus dorsalis, Goldf., Bonn Mus.). 



Ibid., p. 3G9, pi. xxxv, fig. 5, 1840. 

 Strigocephalus Burtini, Phillips. Figs, and Descrip. of the Palaeozoic Fossils of Corn- 

 wall, Devon, and West Somerset, p. 79, fig. 141, 1841. 



— giganteus. Ibid., p. 80, fig. 142. 



Stringocephalus Burtini, F. A. Roemer. Beitrage zur Kenntness des Nordwestlichen 



Harzgebirges in Dunker u. V. Meyer's Paloeontographica, 

 vol. hi, p. 24, pi. x, fig. 2, 1850. 

 Uncites LiEVis, M'Coy. British Palaeozoic Fossils, p. 380, pi. ii A, fig. 6, 1852. 

 Stringocephalus Burtini, Schnur. Beschreibnng Eifel. Brachiopoden, p. 195, pi. xxviii, 



fig. 5 ; pi. xxix, fig. 1 ; pi. xxxi, fig. 1, 1853. 



— — Davidson. Introduction, p. 73, pi. vii, fig. 98, and French 



Ed., Mem. de la Soc. Linneenne de Normandie, vol. x, p. 74, 

 figs. 45—50, 185G. 



— — Sness. Zur Kenntniss Stringocephalus Burtini, Verhandl. d. z. 



b. Vereins, iii, 1853, and German Ed. of Davidson's Intro- 

 duction, pi. i, fig. 16, 1856. 



— hians, Sandberger. Die Brachiopoden Kheinischen Schichtensystems in 



Nassau, p. 31, fig. 4, 1855. 



Spec. Char. Shell very variable in shape, suborbicular, transversely or longitudinally 

 oval ; valves usually either evenly convex, without fold or sinus, or with, sometimes, a more 

 or less distinct median groove upon each valve. Ventral valve usually somewhat deeper 

 than the ventral one ; beak incurved, more or less prominent, entire and pointed at its 

 extremity ; hinge-area distinct, and in the young age divided by a large fissure, which 

 becomes with age gradually surrounded by the deltidium, so as to become oval, and even 

 sometimes finally closed, in some adult individuals. External surface smooth, and, when 

 perfectly preserved, covered with very fine, delicate, slightly undulated, longitudinal 

 strise. Valves articulating by means of a large prominent tooth situated on either 



