 Beaks moderately elevated above the hinge-line, slightly incurved, situated about one-third the length of the shell from the anterior extremity, connected with the posterior basal extremity by a slightly arcuate, subangular, umbonal ridge.  Transactions of the Academy of Science of Saint Louisby Academy of Science of St. Louis - 1856Snippet view - About this book
 | New Jersey Geological Survey - Paleontology - 1907 - 890 pages
...length, 24mm.; height, 2o mm.; thickness, 15 mm. Shell subovate in outline; the beaks large, prominent, slightly incurved, situated about one-third the length of the shell from the anterior extremity. Hinge-line arcuate ; anterior margin rather narrowly rounded; basal margin convex, curving upward more... | |
 | New Jersey Geological Survey - Paleontology - 1907 - 934 pages
...length, 24 mm.; height, 2o mm.; thickness, 15 mm. Shell subovate in outline; the beaks large, prominent, slightly incurved, situated about one-third the length of the shell from the anterior extremity. Hinge-line arcuate; anterior margin rather narrowly rounded ; basal margin convex, curving upward more... | |
 | Nelson Horatio Darton - Geology - 1910 - 574 pages
...tapering from the beaks toward the posterior extremity, which is narrow and sharply rounded; beaks situated about one-third the length of the shell from the anterior extremity, very small, closely approximate, pointing posteriorly; cardinal line, posterior of the beak, elevated... | |
 | Geological Survey (U.S.) - Geology - 1911 - 188 pages
...tapering from the beaks toward the posterior extremity, which is narrow and sharply rounded; beaks situated about one-third the length of the shell from the anterior extremity, very small, closely approximate, pointing posteriorly; cardinal line, posterior of the beak, elevated... | |
 | Maryland Geological Survey - Geology - 1916 - 576 pages
...Large individuals grow to a length of 50 mm. or more. Shell broadly subovate in outline, beak obtuse, situated about one-third the length of the shell from the anterior extremity. Antero-cardinal margin straight or slightly concave, sloping downward from the beak : anterior margin... | |
 | Maryland Geological Survey - 1916 - 552 pages
...Large individuals grow to a length of 50 mm. or more. Shell broadly subovate in outline, beak obtuse, situated about one-third the length of .the shell from the anterior extremity. Antero-cardinal margin straight or slightly concave, sloping downward from the beak ; anterior margin... | |
 | Missouri. Division of Geological Survey and Water Resources - Geology - 1917 - 1040 pages
...behind, the width a little more than one-half the length. Beaks prominent, Incurved above the hinge-line, situated about one-third the length of the shell from the anterior extremity. Cardinal margin slightly convex from the beak anteriorly, and concave posteriorly to the posterior... | |
 | Helen Morningstar - Paleontology - 1922 - 358 pages
...slightly so at the posterior margin; beak directed posteriorly, prominent, elevated above hinge line and slightly incurved, situated about one-third the length of the shell from the posterior margin; anteriordorsal margin long, sloping downward from the beak to the anterior extremity... | |
 | Lloyd William Stephenson, Mary Jane Rathbun - Decapoda (Crustacea) - 1923 - 832 pages
...collection. Shell elongate, trapezoidal, moderately convex. Beaks incurved, rather distant, prosogyrate, and situated about one-third the length of the shell from the anterior extremity; the umbonal portion of the shell projects somewhat above the hinge line. Umbonal ridge oblique, subangular... | |
 | Geology - 1952 - 436 pages
...strongly and broadly inflated, inequilateral. Beaks prominent, very strongly incurved, prosogyrate, situated about one-third the length of the shell from the anterior extremity. Dorsal slopes overhanging in the umbonal region. Umbonal ridge sinuous, strongly curved below, obtusely... | |
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