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next meet, in the temperate and warmer regions generally, the smaller 

 Capreoline and Rusiae forms, decreasing in size southward, with a rapid 

 reduction 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 Cariacine deer of North America. 



The Canidce form another family, which, while having a nearly cos- 

 mopolitan distribution, is most numerously represented in the temper- 

 ate 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 Mexico, 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 Cariaciue Deer. 



The Ursidce, while having a wide geographical range, are confined 

 mainly to the north hemisphere, throughout which they have representa- 

 tives. Here again the larger species are northern, while all the warm- 

 temperate and subtropical forms are small. There is also a correspond- 

 ing decrease in size southward among the representatives of the several 

 species. (See later portions of the paper for a somewhat detailed dis- 

 cussion of the North American species.) 



The Mustelidce, while mainly confined to the northern hemisphere, 

 have also representatives south of the equator. Of the Mustelines prop- 

 er, 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 mid- 

 dle-temperate latitudes, with a single species occurring (only at consid- 

 erable altitudes) under the tropics. Galictis is its single tropical repre- 

 sentative, 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 largest representatives 

 of the family. The Mephitince, 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 range, 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 maxi- 

 mum 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 



