BRACHIOPODA, 
187 
live of R. cuneata has been regarded as a variety of the specific type, var. 
Americana, Hall. It occurs sparingly in the Niagara fauna of New York, but 
abounds at Waldron, Indiana, and is not uncommon in the dolomites of Illinois 
and Wisconsin. In Great Britain, however, the species appeared earlier, being 
found, according to Davidson, in the Lower Llandovery if not even in the 
Upper Caradoc. 
Genus STENOSCHISMA, Conrad. 1839. 
PLATE LVI. 
1839. Stmoscisma. Conkad. Second Ann. Kept. Pala3ont. Dept., p. 59. 
1859. Rhynchonella, Hall. PaliEontology of New York, vol. iii, ji. 236, pi. xxxv, figs. 6«-?/. 
1867. Stenocisma, Hall. Paleontology of New York, vol. iv, pp. 334, 335. 
Mr. Conrad, in speaking of the rocks and fossils of the State of New York, 
in his Second Annual Report (p. 59), makes use of this term for shells, the 
only representative of which specified by him, is “the common Silurian bivalve 
Terehralula Schlotheimii, Von Buch.” The T. Schlotheimi is a well-known Per¬ 
mian, not Silurian species, and some writers, notably Dr. HIhlert in Fischer’s 
Manuel de Conchyliologie, have considered it necessary to apply the term 
Stenoschisma (Stenoscisma as written by Conrad) in accordance with the 
characters of von Buch’s species, which renders it equivalent to King’s genus, 
Camarophoria (1845). It is important in such a matter to get as near as 
possible to Mr. Conrad’s intentions; that he was at a disadvantage in draw¬ 
ing comparisons or making identifications of American with European 
species is evident from his characterization of T. Schlotheimi as a “ common 
Silurian bivalve.” 
Unquestionably he had before him at the time, and intended by this designa¬ 
tion some New York species, and in Volume IV of the Palaeontology of New 
York (p. 334) the author states that Mr. Conrad had used this name on a lith¬ 
ographed but unpublished plate of the fossils of the ,Lower Helderberg group, 
to designate a species subsequently described* as Rhynchonella formosa. Hall. 
This is as close an approximation to Mr. Conrad’s conception as is now possible 
* Palaeontology of New York, vol. iii, p. 236. 
