282 PALEONTOLOGY OF NEW YORK. 



Gbmos STRINGOCEPHALUS, Defrance. 1827. 

 (emend. Sandberger. 1842.) 



1837. StrygocephaIu-1, Dbkbancb. Diction. <\ea Sciences Nat., vol. li, p. 102, Atlas pi. Ixxv, fijfs. 1, lo. 



1827. Ter^tratnla, Sowbrbt. Mineral Concholoiry. I'l- <1Ixxvi, fig. 1. 



1834. IVrebratula, von Buck. Ueber Terebraleln, p. 117. 



1839. StrigocepfiaJua, Sowerby. Trims. Geol. Soc. London, vol. v, second ser., pi. Ivi, figs. 10, II. 



1840. Strygocephalus, D'AncuiAC and db Vbrmbuil. Trans. Geol. Soc. London, vol. vi, 2 sei-., p. 398. 



1841. StrigucepJiatus, Phillips. Palseoz. Foss. Cornwall, Devon and West Somerset, p. 79, fig. 141. 



1842. Stringocephalns, Sandbbboer. Leonhard und Broiin's Jahi-buch, p. 386. 



18C0. Stringoctphalus, F. Robmek. Beitr. zur Kenntn. des nordw. Harzgeb., p. 24, pi. x, fig. 2. 



1862. Vncites, McCoy. British PaliEoz. Foss., p. 380, pi. iiA, fig. 6. 



1863. Stringoceplialus, Schsdr. Beschreib. Eifel. Brachioi>oden, p. 196, pi. xxviii, fig. 6 ; pi. xxix, 



fig. 1; pi. xxxi, fig. 1. 

 Is60. Slrigocephalu8, Kino. Pei-mian Fossils, p. 70, pi. xix, fig. 1. 



1863. Stringocephalns, Sbbss. Verb, der zool. bot. Vereins zu Wien, vol. iii. 



1855. Stringocephalus, The Sandbbrgers. Vei-st. des rhein. Schicht. Syst. in Nassau, p. 307, pi. xxxi, 



fig. 4o-d. 



1866. Stringoctphalus, Davidsom. Inti eduction Biit. Bracbiopoda, p. 73, pi. vii, fig. 98. 



1858. Stringocephalm, 80B8S. Class, der Bracb. von Th. Davidson, p. 62, pi. i, fig. 16. 



1864. Stringocephalus, Davidson. Biit. Devon. Biachioiioda, p. II, pi. i, figs. 18-22; pi. ii, figs. 1-11. 

 1871. Strigocephalus, Qdbnstbdt. Brachiopoden, p. 234, pi. xliii, figs. 58-75 ; pi. xliv, figs. 1-8. 

 1871. Stringocephalus, Kaysbr. Zeitscbr. der deutsch. geolog. Gesellsch., vol. xxiii, pi. di. 



1891. Stringocephalus, Whitbavks. Contrib. Canad. Palaeont., vol. i, No. 5, p. 23.i, pi. xxix, figs. 10, 

 lOo, 11, 11a. 



Shell varying in outline from transverse to elongate-oval, biconvex; the 

 brachial valve being somewhat the deeper; the greater convexity is in the 

 umbonal region, giving to the brachial valve a high-shouldered appearance. 



On the pedicle-valve the beak is somewhat narrow, its apex being abruptly 

 attenuate, acute and often greatly incurved. From beneath the beak diverge 

 two sharp ridges extending to the extremities of the hinge and delimiting the 

 broad cardinal excavations which seem to constitute a true cardinal area. The 

 delthyrium is broad and triangular ; in young shells it may be wholly open or 

 incompletely closed by the imperfectly developed deltidial plates, while at 

 maturity it is closed with the exception of a circular foramen, and in old shells 

 the deltidial plates are anchylosed, forming a single plate which becomes 

 incurved, and the foraminal passage is thus obscured, and may take the form 

 of a tube or sheath prolonged into the umbonal cavity. 



On the interior the teeth are short, free and curved upward at their extrem- 

 ities. In the middle of the valve is a vertical longitudinal septum, which 



