rth of
the eighth pass and the other specimen, No. 35473, was obtained a few
hundred yards south of the pass. Because the part of the barrier beach
south of the pass was connected to the mainland, it is likely that the
newly named subspecies occurs also on the adjacent mainland; however, we
have examined no specimens of _Lepus californicus_ from the opposite
mainland except from Matamoros, ninety miles to the north, and from
Altamira, approximately one hundred and fifty miles south of our
collecting locality. A specimen from Matamoros, Tamaulipas, and several
from Brownsville, Texas, in size of auditory bullae, larger overall size
and darker color clearly are _L. c. merriami_ and not _L. c. curti_.

The small tympanic bullae of the specimens from Padre Island were
commented upon by Nelson (_op. cit._:149) who found smallness of bullae
to characterize many of the specimens from the eastern part of the
geographic range of _L. c. merriami_. In the northeastern part of the
geographic range of _L. c. merriami_, as Nelson pointed out, the small
size of the tympanic bullae was one of several evidences of
intergradation there with _Lepus californicus melanotis_, the subspecies
next adjacent to the north. In the light of present information, it
seems that the smallness of the tympanic bullae in the specimens (3)
from Padre Island may be an independent development--an adaptation to
environmental conditions that reaches its fullest development on the
same chain of islands eighty-odd miles southward of Matamoros. The
specimens from Padre Island, although possessing small bullae, in other
features, for example, larger size of other parts, are _merriami_.

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