. Contributions to a revision of the North American beavers, otters and fishers. Beavers; Otters; Fishers. 348 NOTES ON THE CANTON OF THE WHITE EIVER OLIGOCENE. that of me. ii and is of a more quadrate section, the dorsal and lateral surfaces forming- distinct angles. The fourth metacarpal has a narrow, hut deep head, which projects prominently behind the plane of the shaft ; the facet for the unciform is slightly concave in the transverse and strongly convex in the dorso-palmar direction. Compared with the cor- responding bone of Canis, the following differences in the shape of the facets for
. Contributions to a revision of the North American beavers, otters and fishers. Beavers; Otters; Fishers. 348 NOTES ON THE CANTON OF THE WHITE EIVER OLIGOCENE. that of me. ii and is of a more quadrate section, the dorsal and lateral surfaces forming- distinct angles. The fourth metacarpal has a narrow, hut deep head, which projects prominently behind the plane of the shaft ; the facet for the unciform is slightly concave in the transverse and strongly convex in the dorso-palmar direction. Compared with the cor- responding bone of Canis, the following differences in the shape of the facets for the adjoining metacarpals may be observed. The surface for mc. iii is, as in the recent animals, divided into dorsal and palmar portions, but they are not completely separated; the dorsal moiety is much larger, but not nearly so prominent, and the palmar portion is much smaller. The facet for mc. v is of about the same sha])e in both genera. The shaft is slender and nearly straight, but slightly arched toward the dorsal side; though relatively short, it considerably exceeds mc. ii in length. The prominence of the lateral ligamentous processes gives great proportionate breadth to the distal end. The trochlea is like that of mc. ii, except for its greater size and presents the same differences from the modern type. The fifth metacarpal has been lost from the specimen. The phalanges are very remarkable, but can be most conveniently described in con- nection with the pes, with which the most complete specimens are associated. Measurements. No. Scapho-lunar, breadth " " depth (dorso-palmar) Metacarpal i, length , " breadth of proximal " distal end " distal Metacarpal ii, length " breadth of proximal " " distal end " " Metacarpal iii, breadth of proximal end. Metacarpal iv, length ' breadth of proximal " " distal end " " " trochlea. .026 .009. Please note tha
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectotters, bookyear1898
