Description of a New Genus (Phenacomys) and Four New Species of Arvicolinæ

Abstract

The genus which is the subject of the present paper is of unusual interest, inasmuch as it is the most central or generalized form yet dis covered in the Arvicoline series. It not only combines in a remarkable manner the characters of the Arvicoline genera My odes, Synaptomys, Cuniculus, Arvicola, and Evotomys, but is near if not in the direct line of descent from the Murine series. It was first brought to my notice by Dr. George M. Dawson, Assist ant Director of the Geological and Natural History Survey of Canada, who sent me for identification a specimen collected by him near Kamloops, British Columbia, October 2,1888. Dr. Dawson had no facilities for the preparation of this kind of material, hence the specimen reached me in the form of a rough skin, turned inside out to dry, with the broken skull attached. Fortunately the feet, tail, and teeth were pre served-enough to furnish the most important characters. So far as external features are concerned-size, proportions,' and colorationthere is nothing to indicate that the animal might not be a pale indi vidual of the common eastern meadow mouse or vole {Arvicola riparius), but the skull and teeth differ essentially from those of any previously known genus. All of the molars in both jaws are rooted, each having two true divergent roots, instead of growing from a persistent pulp, as in Arvicola. The crowns of the upper molars, in the number and ar rangement of their triangles, resemble those of the Mississippi Valley voles of the subgenus Pedomys, while they agree with Evotomys in the large size of the dentine islands and the crowding of the teeth. The crowns of the.lower molars not only differ from those of any section of the genus Arvicola, but resemble in certain respects the correspond ing teeth of the singular genera Myodes, Synaptomys, Cuniculus, and Evotomys. * Phenacomys, from ψένα^-α cheat, an imposter; and /ic; = a mouse, in reference to the circumstance that the external appearance of the animal gives no clue to its real affinities.

Cytochrome-bSequence Variation in Water Shrews (Sorex palustris) from Eastern and Western North America

“…In addition, S. bendirii is morphologically (dark venter and indistinct toe fringes versus silver-gray venter and distinct toe fringes in S. palustris) and ecologically (broadly associated with wet habitats versus a more strict association with running streams for S. palustris) distinctive, although some overlap exists (Pattie 1973;van Zyll de Jong 1983;Beneski and Stinson 1987). Merriam (1884) and Jackson (1928) observed morphological convergence in some characters but concluded there was no evidence for morphological intergradation.…”

Canadian Voles of the Genus Phenacomys with Description of Two New Canadian Subspecies

“…More recent material which has come to hand seems to show that the great» geographical gap existing at that time between wngava and mackenzw has been fairly well bridged by the taking of specimens at Favourable Lake, Kenora district, in northwestern Ontario, 500 miles northwest of the Franz records in Algoma district, approaching nearer to wngava than to any other form, but showing relationships to mackenziw; one specimen 300 miles southwest of Favourable Lake at Riding Mountain, Manitoba; five others still farther' northwest near Prince Albert National Park, Saskatchewan; and two others at Battle Lake in central Alberta belonging to the prairie form and approaching mackenzii to some extent. The specimens from the central parts of the Prairie Provinces, while not taken in strictly prairie conditions, but from elevated portions of the prairie region, near the merging of the Great Plains with the northern forested regions, seem to justify the naming of a new geographieal race which appears to show the connection between Phenacomys ungava Merriam (1889) Under parts light grayish in appearance, hairs black at base and tipped with white, fairly distinet from dorsal region, but with whitish encroaching a little at middle of flanks. Tail and feet with hairs mostly white, giving a_ whitish appearance where hairs are present.…”

“…Dr. Merriam (1889) Owing to the boreal habitat of the representatives of this genus, both in the western mountains of North America and the northern forested region east of the mountains, as well as to the apparently local distribution of these animals, comparatively few specimens have come to light and the progress of our knowledge has been slow, although many more specimens have been obtained of the intermedius group, ranging from the Rocky Mountains westward, than of the ungava group, which ranges from the eastern foothills of the Rocky Mountains to the Atlantic coast of Labrador.…”