BRACHIOPODA. 189 



in it a nearer relationship to Rhynchotrema, than to the Silurian and Devonian 

 representatives of Camarotcechia ; in other words, the existence or absence of 

 the median brachial septum should be regarded as of less significance than the 

 co-existence of a similar type of hinge-structure. 



In exterior characters Stenoschisma formosa is a trihedral, strongly plicated 

 shell with well-developed fold and sinus, of an expression not unconiinon 

 throughout the Devonian rhynchonellids. 



Genus CAMAR0T(ECH1A, nom. nov. 



• PLATE LVII. 



1841. Atrypa, Conrad. Ann. Rept. PaL-eont. Dept. N. Y., p. .55. 



1843. Atrypa, Hall. Geology of New York ; Rept. Fourth Dist. ; Tables of Organic Remains, No. 6(j, 



figs. 3, 4 ; No. U7, fig. 2. 

 1847. Atrypa, Hall. Palaeontology of New York, vol. i, pp. iil, 23, pi. iv (liis), figs. 7, 9. 

 1852. Atrypa, Hall. Paleontology of New York, vol. ii, p. 70, pi. xxiii, figs. 4, 5 ; p. 274, i)I. Ivii, 



fig. 1 ; p. 279, pi. Iviii, figs. 3, 4. 

 1857. Rhynchonella, Hall. Tenth Ann. Kept. N. Y. State Cab. Nat. Hist., p. 78, figs. 1-7 ; p. 82, 



figs. 1-3 ; pp. 81, 86. 

 1860. Rhynchonella, Billings. Canadian Journal, vol. v, pp. 271, 272. 



1860. RliyndioneUa, Hall. Thirteenth Ann. Rept. N. Y. State Cab. Nat Hist., pp. 87, 88. 

 1862. Rhynchonella, A. Winchell. Proc. Acad. Nat. Sci. Philadelphia, pp. 407, 408. 

 1862. RhyiicJwTiella, BihUUGS. Pala'ozoic Fossils, vol. i, pp. 141-143, figs 118-120. 

 ]S63. Rhynchonella, Hall. Transactions of the Albany Institute, vol. iv, ]>p. 215, 216. 

 1867. Rhynchonella {Stenvcisina), Hall. Palojontology of New York, vol. iv, pp. 335-345, 348-353, 



pi. liv, figs. 1-59 ; pi. liv a, figs. 1-23, 44-49 ; jil. Iv, figs. 1-52. 

 1879. Rhynchonella, Hall. Twenty-eighth Rept. N. Y. State Mus. Nat. Hist., pp. 163, 164, pi. xxvi, 



figs. 12-33. 

 1882. Rhynchonella, Hall. Eleventh Ann. Rept. State Geologist of Indiana, pj). 305-307, pi. xxvi, 



figs. 12-33. 

 1884. Rhynchmiella, Walcott. Monogr. U. S. Geol. Survey, vol. viii, p. 152, pi. xiv, fig. 3; j)l. xv, 



fig. 6 ; p. 155, pi. xiv, fig. 8. 



1887. Rhynchonella, Gosselbt. Annates de la Soci6le Geologique du Nord, vol. xiv, p. 188, 



l>ls. i-iii. 



1888. Rhynchonella, Herhick. Bulletin Labor. Denison University, vol. iii, pp. 39, 40, \A. v, fig. 1 ; 



pi. vii, fig. 25 ; pi. x, fig. 9. 



By restricting the application of the term Stenoschisma to shells agreeing in 

 hinge-structure with Rhynchonella formosa, the necessity is created for ;i new 

 designation for the large group of shells to which that term was applied in 

 1867.* While these shells are susceptible to considerable variation in exterior, 



* Paleontology of New York, vol. iv. 



