. Annual report. New York State Museum; Science; Science. Myalina p t e r i n a e oi d e s of the shell. The valves are shallow and thick; posterior muscle scar well defined, situated at one half the length of the shell; pallial line short, barely reaching middle; anterior scar absent. The surface of the shell is coarsely rugose in concentric growth lines and is without other ornament. Of such a species as this we Jmow nothing among the faunas of the Appalachian early Devon ic. Lower Devonic. Presque Isle stream, Chapman Plantation, Me. Cyrtodonta beyrichi Beushausen Cyrtodonta beyr
. Annual report. New York State Museum; Science; Science. Myalina p t e r i n a e oi d e s of the shell. The valves are shallow and thick; posterior muscle scar well defined, situated at one half the length of the shell; pallial line short, barely reaching middle; anterior scar absent. The surface of the shell is coarsely rugose in concentric growth lines and is without other ornament. Of such a species as this we Jmow nothing among the faunas of the Appalachian early Devon ic. Lower Devonic. Presque Isle stream, Chapman Plantation, Me. Cyrtodonta beyrichi Beushausen Cyrtodonta beyrichi Beushausen. Beitr. zur. Kenntn. d. Ob- erharzen Spiriferensandsteins. 1884. p. 67, pi. 3, fig. 2, 3. I am disposed to refer to this species without much reservation certain subcircular shells of Paracyclaslike outline with quite con- vex surface, slightly depressed behind and faintly sinuous in front. In these the hinge has the structure of Cyrtodonta strongly de- veloped—the curved double anterior teeth and the long lateral or posterior grooves and ridges. Beushausen's figures were made from internal casts but they display the general outline and size of those before us. The genus Cyrtodonta has not been observed in the Devonic rocks of the Appalachian province and its occurrence in the eastern. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original New York State Museum. Albany : University of the State of New York
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