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Show 311 next meet, in the temperate and warmer regions geuerally, the smaller Gapreoline and Rusine forms, decreasing in size southward, with a rapid redaction also in the size of the antlers. Finally, in the subtropical and tropical portions of the Old World, we meet with antlerless forms, that constitute the smallest species known among the Cervidce and their allies. The decrease in the size of the antlers southward among the different genera and species is also well marked among individuals of the same species, especially among the Gariacine deer of North America. The Canidm form another family, which, while having a nearly cosmopolitan distribution, is most numerously represented in the temperate regions of the northern hemisphere, where - also occur nearly all of the larger species, and where are exclusively found the true Wolves and Foxes. In respect to the latter, the larger species of each occur only at the northward, and the smaller at the southward. Thus, in North America, the large Gray Wolf ranges from the arctic regions to Florida and Mexico, while the Coyote is not found much to the northward of the great campestrian region of the interior. The Common Fox ranges also from the subarctic districts southward to the Gulf of Mexioo, while the smaller Gray Fox finds its northern limit near the parallel of 42°, while a third still smaller species is confined « within the warmer-temperate latitudes. At the extreme northward, we find, however, a smaller arctic form, on the extreme northern confines of the habitat of the family. In the Wolves and Foxes, decrease in size to the southward is strongly marked, being probably not exceeded in any other group, though perhaps nearly equaled in some of the Gariacine Deer. The Ursula, while having a wide geographical range, are confined mainly to the north hemisphere, throughout which they have representatives. Here again the larger species are northern, while all the warm-temperate and subtropical forms are small. There is also a corresponding decrease in size southward among the representatives of the several species. ( See later portions of the paper for a somewhat detailed discussion of the North American species.) The MustelidcBj while mainly confined to the northern hemisphere, have also representatives south of the equator. Of the Mmtelince proper, all the larger species are boreal, though some of the smaller extend also to the arctic regions. The Wolverine, the largest of the group, is the most boreal; the Fisher and the Marten, the next in size, are mainly confined to the subarctic and cold- temperate regions; the Mink, next in size, extends farther southward; the Weasels range also into the middle- temperate latitudes, with a single species occurring ( only at considerable altitudes) under the tropics. Oaliotis is its single tropical representative, and is also the most specialized ( though not the smallest) type of the group. The Melince and Enhydrince, each with a single American representative, and both boreal, are also among the largestrepresentatives of the family. The MephitincB, of medium or rather small size, are strictly a warm- temperate and tropical group, with representatives extending from the northern parts of the United States southward to'the southern parts of South America. The Lutrince have a wider rauge, being found throughout the tropics as well as in the temperate and colder regions, and apparently present not a very great range of geographical variation. The Felidce, while possessing an almost cosmopolitan range, have their greatest development within the tropics, where they attain their maximum size and number of species. The single boreal genus found in America is one of the most specialized forms of the family. As will be shown later, the American representatives of this family present a notable exception to the general law of decrease in size toward the No. 4 3 |
