. A dictionary of the fossils of Pennsylvania and neighboring states named in the reports and catalogues of the survey ... Paleontology. Orthis. 528. Spec. 11,745 (000) Hamilton upper shale ; Jericho school house, 12,020, ditto', Crawley hill, 12,460, ditto,—In Columbia Co. Hemlock, Fishing Creek Section, in a richly fossiliferous bed 100' beneath the top of the Hamilton. G7, p. 75, 229.— In the Oil region, CarlPs collections, Upper Chemung (C. E. Hall, MS. Rt. Dec. 30,1876.)—F///^; ( Vlll-lXf) Orthis pennsylvanica, new species, Simpson, Trans. Am. sm y-^rv^ fv ..^ ^ 'e\i\\o%, Soc. 1889, Vol.
. A dictionary of the fossils of Pennsylvania and neighboring states named in the reports and catalogues of the survey ... Paleontology. Orthis. 528. Spec. 11,745 (000) Hamilton upper shale ; Jericho school house, 12,020, ditto', Crawley hill, 12,460, ditto,—In Columbia Co. Hemlock, Fishing Creek Section, in a richly fossiliferous bed 100' beneath the top of the Hamilton. G7, p. 75, 229.— In the Oil region, CarlPs collections, Upper Chemung (C. E. Hall, MS. Rt. Dec. 30,1876.)—F///^; ( Vlll-lXf) Orthis pennsylvanica, new species, Simpson, Trans. Am. sm y-^rv^ fv ..^ ^ 'e\i\\o%, Soc. 1889, Vol. sentially circular, in nearly all the specimens S''^:''liy.:i^^^^ teSSfelsl^^^ observed, the height and v/i'.'//h. t!!^^^m m;:i^mi--mam^^ Width being equal; hinge line short, length equal APS) ^; to half the width of the shell; cardinal extremities rounded; lateral and basal mar- gins regularly rounded, except in the middle basal margin of the ventral valve, where there is a slight constriction. Dorsal valve somewhat gibbous, greatest convexity a little above the middle; rapidly curving to the cardinal and lateral margins ; a little more gradually to the basal margins. Along the mid- dle of the valve is a flattened or slightly depressed area, nar- row at the beak, gradually growing wider, and comparatively broad at the base. Ventral valve. A perfect specimen has not been observed, but gutta-percha casts have been taken from impressions of fragments in the rock which probably be- longed to this specie^. The valve is flattened, or of much less convexity than the dorsal valve, with a slight elevation along the middle, corresponding to the depression of the opposite valve. Surface marked by prominent, subangular, radiating striae, increasing by bifurcation, of uniform size at the margins, where there are twelve in the space of 5 mm.; a short distance below the beak there are twenty in the same space. The radii are crossed by fine indistinct concentric striae, w
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectpaleontology, bookyea
