Myotis keaysi

DIAGNOSIS. Myotis keaysi (Fig. 1) is smaller than M. ruber. Compared with M. nigricans, fur is shorter and woollier, size of wing is larger, and width across canines to postorbital constriction is larger (M. keaysi: maximum, 1.12 mm; M. nigricans: minimum, 1.00 mm). In M. keaysi, sagittal crest is present, slope of forehead is steeper, and ratio of width across canines to postorbital constriction is greater than that of M. oxyotus (LaVal 1973). Distribution of fur on uropatagium is more extensive in M. keaysi than M. elegans; distal two-thirds of uropatagium is bare in M. elegans. Sagittal crest is absent in M. elegans but present in M. keaysi. Bacula of M. elegans, M. nigricans, and M. oxyotus are similar in size, but baculum of M. keaysi is wider and triangular in shape (LaVal 1973). Compared with M. californicus, M. keaysi has hair on upper surface of wing and on leg below knee (Reid 1997).