The four specimens of _L. c. curti_ are in worn winter pelage and the new pelage is coming in on the thighs. Most of the specimens (6) of the _L. c. altamirae_ are in the same condition of pelage. In color and color pattern, the two subspecies are, to me, indistinguishable except that the black patch on the nape is less widely and less definitely separated into two parts by a median, longitudinal, band of buffy color. _Lepus californicus altamirae_ was named by Nelson (Proc. Biol. Soc. Washington, 17:109, May 18, 1904) as a black-tailed jack rabbit, _Lepus merriami altamirae_, but was later transferred by Nelson (N. Amer. Fauna, 29:124, 1909) to the white-sided section of the genus and arranged as a full species, _Lepus altamirae_. In making this transfer, Nelson (_op. cit._:125) wrote that in "This well marked species ... the lack of a black patch on the posterior half of the ear at the tip and the white flanks (somewhat obscured in some of the original specimens) are strong characters which place it in the _callotis_ group." "Posterior half of ears white without any trace of black at tip", was the way Nelson (_op. cit._:124) described the ears in _L. altamirae_. My examination of the original series including the type, reveals that the ears do have some black at the tip of the posterior half in three of the specimens, some brown in one other specimen, and only a dusky tinge in two others. In the four specimens of _L. c. curti_ the tip of the ear is faintly brownish in one animal and dusky in three. The extent of the white flanks seems to be identical in the two series. Fortunately they are in the same pelage and same stage of molt on the hind legs. The one difference that I can detect is in the coloration of the nape. In each of the specimens of _L. altamirae_ the coloration is as described by Nelson (_op. cit._:124): "nape with two lateral black bands extending back from base of ears, and separated by a median band of buffy." In _L. c. curti_ the nape is all black in one specimen and the median band of buffy is present in the other three but is narrower and more dusky than in _L. altamirae_. Since the characters (color of tip of ear and extent of white on the flank) relied upon by Nelson for placing _L. altamirae_ in the _callotis_ group are duplicated in the _californicus_ group, in _L. c. curti_, there is reason for questioning whether _altamirae_ is correctly placed, taxonomically, in the _L. callotis_ group.