204 PALEONTOLOGY OF NEW YORK. 



BILOBITES, LiNNE. 1775. 



IX. Group of Orthis biloba, Linne. 



Anomia biloba, Linne. 



PLATE Vb, figs. 11-19. 



m^. Bilobites, Linne. Systema Natura;, ed. Miiller, voL vi, p. 325. 



181."). Terebratula, J. Sowerby. Ti'ans. Linn. Soc, vol. xii, p. 516. 



1826. Terebratula. Htsingeb. Anteckn. Act. Royal Soc, Holm., pi. 7. 



1827. DeUhyrls? Dalman. Vetensk. Svenska Akad. Hand., p. 124, pi. 3, fig. 7. 



1828. Delthyris, Hisinger. Bidi-ag- till Svei-iges g-eognosi, vol. iv, p. 220. 



1837. t^irb-ifer, von Buck Abhandl. Konigl. Akad. d. WisEensch. zu Berlin, p. 49. 



1837. Deltliyi-U, RiHJUGER. Lethaja Suecica, p. 74. 



1838. Delthyris, Conrad. Second Ann. Kept. Geol. N. Y., pp. 112, 118. 



1838. Terebratula {DeUhyris?) Angblik. Museum PaljEOnt. Suecicum. 



1839. Spirifer, Sowerby. Murchison's Silurian System, p. 630. 



1842. DeUhyris, Conead. Journ. Acad. Nat. Sci. Pliila., vol. viii, p. 262. 



1843. DeUhyris, Hall. Geology of N. Y. ; Kept. Foui-th District, p. 105. 



1847. S%iiriftr, de Vekneuil. Bull. Soc. Geol., France, 2d ser., vol. iv. 



1848. OrtMs, Davidson. Bull. Soc. Geol., Finance, 2d ser., vol. v, p. 321. 



1849. Spirifer, Hall. American Journal Science, vol. xx, p. 228. 



1850. Dicwlosla, King. Monogr. Perm. Fossils, England, p. 106. 

 1852. Orthis, McCoy. British Palajozoic Fossils, p. 213. 



1852. Spirifer, Hall. Paljeontology of N. Y., vol. ii, p. 260. 



1853. Orthis, Davidson. Inti-od. British Fossil Brachiopoda, p. 101. plate viii, figs. 141-145. 

 1859. Orthis, Salter. Mnrchison's Siluria, 2d ed., p. 543. 



1859. Orthis, Hall. P.alsontology of N. Y., vol. iii, p. 179. 



1859. Orthis, Hall. Twelfth Ann. Rept. N. Y. State Cab, Nat. Hist., p. 85. 



1860. Orthis, Lind.sti!om. Gotland's Brach. ; Ofver. Kong. Akad. Forhandl., p. 370. 



1866. OrtMs, Ramsay and Salter. Mem. Geol. Survey United Kingdom, vol. iii, pp. 267, 361. 



1868. Orthis, Davidson. Ti'ans. Geol. Soc. Glasgow, Pal. Sei'ies, vol. i, pi. 2, fig. 2. 



1869. Orthis, Davidson. British Siluriiin Bi'achiopoda, p. 206. 



1882. Orthis, Hall. Eleventh Ann. Rept. State Geologist Indiana, p. 286. 



1883. Orthis [Diccelosial, Hall. Kept. N. Y. State Geologist for 1882, plate xxxv. 



1884. Orthis, Davidson. British Fossil Brachiopoda, General Summary, pp. 377, 433. 

 1888. Orthis, Ringueberg. Proc. Acad. Nat. Sci. Phila., p. 134. 



18S9. Bilobites, Hall. Bulletin Geological Soc. America, vol. i. p. 21. 



Shells small, strongly bibbed. Hinge-line short ; teeth and sockets obscure ; 

 cardinal process small and simple. Crural plates thin and very long, often 

 extending as far forward as the commencement of the lobation. Muscular 

 area indistinct, larger in the brachial than in the pedicle- valve. Shell-sub- 

 stance fibrous and punctated by coarse tubules apparently arranged in radiat- 

 ing rows. 



This group comprises but two species, Orthis biloba, Linne and 0. varica, 



