• 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 88

More information
  • digital collection
  • archival collection guide
  • transcription tips
 
Saving...
[page]87.[/page] Norwood and [?Pratlen?], 1854; muricatus, N. and P., 1854; orbignyanus, Geinitz, 1866; horridus Geinitz, 1866. Shell small, ratio of length to breadth nearly as three to five, breadth one half to three fourths of an inch; general outline semi-elliptical with front slightly emarginate; and ears rather extended; hinge line straight, longer than width of valve at any other point. Dorsal valve abruptly and deeply concave following nearly the curve of the other valve, thus making the fossil thin. A small mesial ridge present; surface apparently without spines. Ventral valve extremely convex, greatest convexity in [?umbonal?] region, curving more abruptly posteriorly and laterally than toward the front; umbo projecting beyond the hinge line, beak small.
 
Scholarship at Iowa