. Annual report of the Regents. New York State Museum; Science. 192 NEW YORK STATE MUSEUM Genus rhynchotreta Hall [Ety.: puyxo?, beak; rprjrd, with a hole] (1879. ^' ^' ^^^^^ ^^^^^•^- ^^^- ^^^^- ^8^^ ^^' ^ep't, P- 166; 1893. Pal N. Y. V. 8, pt 2, p. 185) Shell triangular; surface with angular plications. Beak of pedicle valve straight, produced beyond that of the opposite valve, extremity perforate, the foramen with an elevated margin. Two longitudinally striated deltidial plates fill the delthyrium. Teeth slender, curving, proceeding from a broad curving hinge plate in the pedicle valve. Brac
. Annual report of the Regents. New York State Museum; Science. 192 NEW YORK STATE MUSEUM Genus rhynchotreta Hall [Ety.: puyxo?, beak; rprjrd, with a hole] (1879. ^' ^' ^^^^^ ^^^^^•^- ^^^- ^^^^- ^8^^ ^^' ^ep't, P- 166; 1893. Pal N. Y. V. 8, pt 2, p. 185) Shell triangular; surface with angular plications. Beak of pedicle valve straight, produced beyond that of the opposite valve, extremity perforate, the foramen with an elevated margin. Two longitudinally striated deltidial plates fill the delthyrium. Teeth slender, curving, proceeding from a broad curving hinge plate in the pedicle valve. Brachidium a slightly modified loop. Ehynchotreta cuneata var. americana Hall (Fig. 105). Atrypa cuneata Hall (1852. Pal. N. Y. 2:276, pi. 57, fig. 4a-r) Distinguishing characters. Triangu- lar and cuneiform outline; longer than wide; elongate angular beak of pedicle valve with compressed, fiat or concave sides; wide, deep sinus in adult, extending two thirds to the beak; profound frontal emargination; strong angular plications, three in sinus, four on fold, the two central ones most prominent; numerous regular, fine thread-like concentric striae; minutely papillose surface. Found in the CHnton lenses and the lower Rochester shale and particularly in the Bryozoa beds, where it is abundant; rarely above this. Niagara sections. Also at Lockport and elsewhere (Hall).. Fig. 105 Rhynchotreta cuneata var americana Genus camarotoechia Hall & Clarke [Ety.: , arched chamber; rolxo?, partition] (1893. Pal. N. Y. V. 8, pt 2, p. 189) Shell rhynchonehoid, trihedral in contour, with shallow pedicle and convex brachial valve; no hinge area; beak of pedicle valve projecting and incurved. Surface radially plicate, sinus and fold in pedicle and brachial valves respectively. Distinctive internal char- acters (separating this genus from other " Rhynchonellas ") are: a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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