Plagiostoma truncata Trask, 1856
TRASK, J. B. 1856. Description of three new species of the genus Plagiostoma, from the Cretaceous rocks of Los Angeles. Proceedings of the California Academy of Sciences, 1: 86, pl. 3. [p. 86, pl. 3, fig. 3]
«P. TRUNCATA. Trask.
Plate III. Fig. 3. Shell compressed; rotund-quadrate; about eight flattened, slightly rounded, concentric annulations; anterior margin rounded, and somewhat obtuse below
the middle; ventral margin orbicular; posterior margin bluntly rounded; posterior dorsal margin subangulate; beaks acute above the line of the auricles; anterior auricle rounded in front, striate, and has a small fold extending from the umbones to its anterior margin above its middle, posterior auricle angulate and obtuse posteriorly; beaks anterior to the middle. Length, one and one-tenth inches; — height, one inch. Locality, San Pedro, Cal. Found with the preceding species [P. annulatus Trask].» JOHN BOARDMAN TRASK, 1856
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J. B. Trask, 1856, plate 3.
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