. Fig. 73. Distribution of Sigmodon hispidus al- fredi in Colorado. For explanation of symbols, see p. 9. nasals, , , (); length of maxillary toothrow, , , (). Remarks.—Goldman and Gardner (1947: 57) distinguished S. h. alfredi from other named kinds on the basis of small size and cranial details, and on the basis of more pinkish, less yellowish color of the dorsum and sides. The hypodigm available to Gold- man and Gardner consisted almost entirely of young animals, subadults and young adults. Most of the material was collected in the spring of 1946, an
. Fig. 73. Distribution of Sigmodon hispidus al- fredi in Colorado. For explanation of symbols, see p. 9. nasals, , , (); length of maxillary toothrow, , , (). Remarks.—Goldman and Gardner (1947: 57) distinguished S. h. alfredi from other named kinds on the basis of small size and cranial details, and on the basis of more pinkish, less yellowish color of the dorsum and sides. The hypodigm available to Gold- man and Gardner consisted almost entirely of young animals, subadults and young adults. Most of the material was collected in the spring of 1946, and evidently represented individuals of various ages born the previous year. The small size attributed to alfredi and cranial details supposed to be diagnostic (skull rounded, less angular and less massive than in S. h. berlandieri or S. h. texianus) seem to me to reflect the fact that few adults were available when the subspecies was de- scribed. The color of several individuals from northern Baca County is distinctly pinkish, less yellowish than is usual in texianus, al- though specimens from 2 mi. S and 2 mi. E of Hasty and from 18 mi. N of Lamar do not show the pinkish buff wash. Hansen (1963) referred the latter specimen (CSU 9812) to texianus with good reason. Color is an inade- quate basis for distinguishing subspecies of S. hispidus. Local populations tend to be quite variable in this respect. The color of specimens from southeastern Colorado is well within the range of variation seen in a large series of specimens examined from Green- wood County, Kansas. The subspecies of S. hispidus are in need of revision. When such a study is undertaken, alfredi may be found to be (as I suspect) a synonym of texianus. On the other hand, the name alfredi may be found to apply to cotton rats over a wide range on the Great Plains. In either case, further research probably will contraindicate the conclusion of Goldman and Gardner (1947:58) that alfredi is a ". . long established
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