History of North American pinnipeds, a monograph of the walruses, sea-lions, sea-bears and seals of North America . FIG. 31.—Odobcemis obesus. Adult. coronoid process. These differences are ah1 strongly pro-nounced in even quite young skulls, this being especially thecase with respect to the inferior border of the symphysial por-tion of the jaw (Figs. 32 and 34). Another difference consistsin the position of the coronoid process, which in the PacificWalrus, especially in the young, is central to the axis of theramus, while in the Atlantic species it rises more from the inner 168 ODOB^NUS OBESU
History of North American pinnipeds, a monograph of the walruses, sea-lions, sea-bears and seals of North America . FIG. 31.—Odobcemis obesus. Adult. coronoid process. These differences are ah1 strongly pro-nounced in even quite young skulls, this being especially thecase with respect to the inferior border of the symphysial por-tion of the jaw (Figs. 32 and 34). Another difference consistsin the position of the coronoid process, which in the PacificWalrus, especially in the young, is central to the axis of theramus, while in the Atlantic species it rises more from the inner 168 ODOB^NUS OBESUS PACIFIC edge, and tlie process itself lias an inward curvature not seenin the other (Figs. 33 and 35). The cranial differences here detailed as obtaining between the Atlantic and PacificWalruses borne out bya large series of the sknlls ofthe two species, numberingnot less than twelve to fifteenof each. There is in each spe-cies a considerable range ofindividual variation; but thedifferences presented by theskulls here figured fairly rep-resent average only exception to bemade is in respect to thetusks of the Pacific speci-FIG. 32.—Odobcenn8 rosmarns. Young, men figured, which are per-haps above the average in size, while they are remarkably di-vergent, more so than in any other specimen of this speciesthat I have seen. Ordinarily, or as a rule, they are more or less convergent, and some-times even meet or overlap,while in the Atlantic speciesthey are, as a rule, in the Pacific speciesthe tusks descend almost ver-tically, in the Atlantic spe-cies they are
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherwashingtongovtprin
