DIY History | Transcribe | Scholarship at Iowa | Coal Measures and Coal Mining in Iowa, including paleontology and a discussion on the coal formation; also the methods of mining by Russell T. Hartman, 1898 | Coal Measures and Coal Mining in Iowa by Russell T. Hartman, 1898, Page 86

Transcribe
Translate

Coal Measures and Coal Mining in Iowa, including paleontology and a discussion on the coal formation; also the methods of mining by Russell T. Hartman, 1898

Coal Measures and Coal Mining in Iowa by Russell T. Hartman, 1898, Page 86

[page]85.[/page]

Productus asper, McChesney, 1860. Descr. New Paleozoic Fossils, p.34.
Strophalosia horrescens, Geinitz, 1866, Carb. und Dyasin Neb., p. 81.
     Size of shell medium, greatest width three fourths to one and a half inches, length and breadth nearly equal, the breadth usually somewhat the greater, the reverse, however is sometimes true; hinge line not quite as long as greatest breadth of shell, cardinal angles flattened. Dorsal valve usually concave, sometimes nearly flat, oblique ridges to lateral margins from beak, beak obscure, cardinal process well defined.
     Ventral valve very ventricose with greatest convexity at umbo which is incurved about the hinge line; posterior lateral slopes descending almost vertically to cardinal angles. Surface of this valve marked by concentric undul-

Saving...

[page]85.[/page] Productus asper, McChesney, 1860. Descr. New Paleozoic Fossils, p.34. Strophalosia horrescens, Geinitz, 1866, Carb. und Dyasin Neb., p. 81. Size of shell medium, greatest width three fourths to one and a half inches, length and breadth nearly equal, the breadth usually somewhat the greater, the reverse, however is sometimes true; hinge line not quite as long as greatest breadth of shell, cardinal angles flattened. Dorsal valve usually concave, sometimes nearly flat, oblique ridges to lateral margins from beak, beak obscure, cardinal process well defined. Ventral valve very ventricose with greatest convexity at umbo which is incurved about the hinge line; posterior lateral slopes descending almost vertically to cardinal angles. Surface of this valve marked by concentric undul-