62 PALAEONTOLOGY OF NEW YORK. 



IMS. Spitifera {Spir\firina), Hall. Second Ann. R.'pt. State Geologist of N. Y., pi. Ix. figs. 19-22, 



26-29; jil. Ixi, tigs. 14-16. 

 1884. Wylrt/Vrino, Wiutk. Thirteenth Repl. Stale Geologist Indiana, p. 135, pi. xxxv, tigs. 13, 14. 

 1884. Spiriferina, Walcott. Monograph U. 8. Geological Survey, vol. viii, pp. 218, 219, pi. xviii, 



figs. 12, 13. 

 1888. 8pbif»rlna, Hbbrick. Bull. Deniaoii Dnivei-sity, vol. iii, p. 47, pi. ii, figs. 9-11 ; pi. v, tig. 13 ; 



pi. X, fig. 8. 

 1891. Spiriferina, Hkrhick. Bnll. Geol. Soc. America, vol. ii, p. 46, pi. i, fig. 19. 



Shells resembling Spibifeb in external aspect; interiorly 

 the pedicle-valve bears a median septum resting upon the 

 bottom of the valve, its posterior portion lying between, 

 but not united with the strong dental lamellaB. The pro- 

 cesses on the primary lamellae are continuous, forming a 

 simple transverse or subacute loop. fig. ii. 



, ii.il. u i. The \oo\> ot Spiryerina Km- 



Shell substance strongly punctate tnrougliout. tuctimsis. suumard. (o 



Type, Terebratulites rostratus, Schlotheim. Lias. 



This name is currently allowed to cover a large number of species presenting 

 the most extreme variations in exterior characters and some important inter- 

 nal differences. The type of the genus is a form upon whose surface the 

 plications are obsolescent and whose epidermis is covered with closely matted 

 spinules ; the median septum is discrete from the dental lamellae, and the loop 

 is a transverse band with a slight upward curve. Recent writers on the 

 Triassic bnichiopods, however, still strain the genus to include species in which 

 the septum unites with and supports the convergent dental lamellae, forming 

 the structure characterizing the interior of Cyrtina.* 



Among the palaeozoic species referred to Spiriferina, the prevailing expres- 

 sion is a strongly plicated exterior with well marked fold and sinus. The 

 shells are usually of small size, and though occasionally with a spiniferous 

 exterior, as in S. spinosa, the usual ornamentation consists of concentric lam- 

 ellae of growth, the surface of which is radially striated and probably minutely 

 fimbriate. The development of the median septum in these species is never 

 8o extreme as in S. rostrata and the Liassic forms. 



* See page 45 of this volume. 



