John E. Guilday

Quaternary periglacial records of voles of the genus Phenacomys merriam (Cricetidae: Rodentia)

Quaternary occurrences of voles of the genus Phenacomys south of the North American continental glaciation range in age from Kansan through early Recent times and are mapped from twenty fossil localities. Phenacomys cannot be used as an index fossil, but makes a good climatic indicator because of its modern boreal affinities. It is largely confined to the present day Canadian and Hudsonian Life Zones of North America.

SUPERNUMERARY MOLARS OF OTOCYON

The occurrence of abnormal upper third molars and lower fourth molars in the Caninae is reviewed. It is proposed that the extra molars normally found in the adult dentition of Otocyon megalotis (Desmarest) are the result of a mutation that caused the duplication of the upper first molar and the lower second molar. Supporting evidence for this is presented. This makes the upper third molar of Otocyon the homologue of the normal canid second molar, and the lower fourth molar the homologue of the normal third molar of all of the remaining canids. The presence of an anomalous upper third molar is a relatively common variant in the genus Canis. Bertram, Windle and Humphreys (1890) recorded ABSTRACT: The occurrence of abnormal upper third molars and lower fourth molars in the Caninae is reviewed. It is proposed that the extra molars normally found in the adult dentition of Otocyon megalotis (Desmarest) are the result of a mutation that caused the duplication of the upper first molar and the lower second molar. Supporting evidence for this is presented. This makes the upper third molar of Otocyon the homologue of the normal canid second molar, and the lower fourth molar the homologue of the normal third molar of all of the remaining canids.

The Prehistoric Distribution of the Opossum

The opossum, Didelphis marsupialis virginiana Kerr, is widely distributed throughout the eastern United States. It occurs as far north as southern Ontario (Peterson and Downing, 1956). Hamilton (1943) gives its range as including Connecticut, Rhode Island, Massachusetts, southern Vermont and southern New Hampshire. It does not occur in the Adirondack Mountains nor in the uplands of New England. The opossum has migrated northward within historic times. Along the Atlantic coast the animal was formerly found no further north than the Hudson River Valley. Goodwin (1935) stated that the spread of the opossum into Connecticut took place “within the last twenty years. ” Brayton (1882) wrote that the animal “is not uncommon in central and southern Ohio, Indiana, and Illinois … the northern portions of these states are not so congenial to it. ” Rhodes (1903), in discussing the distribution of the opossum in Pennsylvania, said: “Variably abundant in middle and southern counties in all situations except in the mountain summits; extending northwards in lessening numbers along …

Archeological Evidence of the Fisher in West Virginia

Kellogg (Proc. U. S. Nat. Mus., 84, No. 3022, 1937) lists reports of the former occurrence of the fisher, Maries pennanti pennanti (Erxleben), from Raleigh, Upshur, and Wetzel counties, West Virginia. He quotes Surber (Proc. 3rd Annual Meeting West Virginia Fish and Game Prot. …