. Cincinnati quarterly journal of science. Science; Science -- Ohio. Brachiopoda of the Cincinnati Ch'oup. 49 the front, and the ventral in the umbonal region ; hinge line equaling the greatest breadth, lateral margins intersecting the hinge nearly at right angles, and rounding to the front, which is regularly rounded, or sometimes faintly sinuous in the middle. Dorsal valve flat at the umbo and raised into a rounded, more or less prominent mesial elevation at the front; beak scarcely distinct from the cardinal margin, which has a very narrow area. Interior. Fig. 5.—Interior of Dorsal Valve. s
. Cincinnati quarterly journal of science. Science; Science -- Ohio. Brachiopoda of the Cincinnati Ch'oup. 49 the front, and the ventral in the umbonal region ; hinge line equaling the greatest breadth, lateral margins intersecting the hinge nearly at right angles, and rounding to the front, which is regularly rounded, or sometimes faintly sinuous in the middle. Dorsal valve flat at the umbo and raised into a rounded, more or less prominent mesial elevation at the front; beak scarcely distinct from the cardinal margin, which has a very narrow area. Interior. Fig. 5.—Interior of Dorsal Valve. showing cardinal process short and deeply bifid, with very diverging socket ridges on each side, and a small mesial ridge extending forward from its base about one fourth the length of the shell; sockets for the teeth of the other valve well defined, and rather wide apart; muscu- lar scars subquadrate and longitudinally furrowed from the socket ridges; vascular markings well defined and somewhat harp-shaped anterior to the muscular scars; punctate structure distinct. Ventral valve a little convex at the umbo, and impressed or bent so as to form a shallow mesial sinus at the front, that rarely extends back to the middle; area well defined, rather high, flat, and a little inclined back over the hinge; foramen closed by a triangular, convex, pseudo- deltidium ; beak not projecting or incurved, but inclined backward with the area and perforated by a minute circular aperture at the apex. Interior with cardinal edge sharp and distinct; hinge teeth oblique, trigonal, and prominent; dental laminse extending forward and curv- ing a little, but not meeting at the ends, forming a deep, somewhat half elliptical cavity, marked with an obscure, central ridge, and parallel radiating furrows. Surface of both valves ornamented by rather fine, more or less bifurcating, radiating striae, which are crossed by finer strise and dis- tinct marks of growth. Length of a large specimen, inch ; bre
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