OCR Text |
Show 323 extremes of variation met with at single localities are as great as those from the most widely separated of the above- named localities; in other words, no geographical variation in size is perceptible. The largest northern specimen ( canadensis)., from Peel River, Arctic America, with a length of 5.30, a little exceeds in size the largest specimens from any locality south of the latitude of 40°; but it in turn is slightly smaller than a specimen ( fasciatus) from Fort Townsend, Wash., which has a length of 5.50, and by another of the same dimensions ( rufus) from the Big Sioux River. Eight specimens of the most southern type ( L. maculatus), all from Texas and the Mexican side of the Lower Bio Grande, differ in the average from nine specimens of the most northern type ( L. canadensis), all from Arctic or sub- Arctic America, almost inappreciably, the canadensis series having an average length of 5.01 and the maculatus series of 5.00! The difference in breadth is also only about one-tenth of an inch, which the addition of a single specimen to either series might cancel. This is certainly a surprising resnlt when it is remembered that one of the chief alleged distinctive characters of L. canadensis has been its supposed larger size! The average dimensions of these several series are as follows: kL. rt( fu9 Mean of all Specie*. Number of specimens. 9 7 8 10 34 Length. & 01 5.03 5.00 4.91 4.96 Breadth. 3.5* 3.56 3.40 3.41 a 47 • The [ mens placed under rt^ fus are those that are so marked in the collection, being the speoi lUned by Professor Beird. The fasciatus series is the largest, but this series happens to include more very old specimens than the others, and hence its higher average. Such a constancy of size as is here shown to prevail over an area embracing more than 40 degrees of latitude is probably without a parallel in any other conspecific group of North American Mammals. Thediffereuce between these heretofore commonly recognized " species" of the genus Lynx must hence be sought elsewhere than in size. The specific distinctness of L. canadensis, the most northern type, has been heretofore scarcely questioned, in consequence of its supposed larger size, larger limbs, longer, softer pelage, longer ear- tufts, more indistinct markings, and generally lighter or grayer color. The longer ear-tufts correlate with the longer, softer pelage, that always characterizes the boreal representatives of species having a wide latitudinal range. The difference in coloration is not greater than, or even so great as, that which obtains between fasciatus and rufus, or between fasciatus and maculatus, which forms naturalists now seem disposed to refer to one and the same species under the name L. rufus. Maculatus, the most southern form, differs from the " typical" or eastern rufus in its shorter, coarser fur, more reddish tints, and more distinct markings. Its reputed range extends from the Lower Rio Grande westward across the continent to Southern California; but in the National Museum collection are also specimens marked rufus from many points within this area, including a considerable series from Fort Tejon. The gradation from the " typical" rufus type into maculatus is complete and by almost insensible stages. |