_Measurements._--The following measurements are of specimens in which the occlusal face of each molar tooth is worn flat. The first measurement is of the holotype followed by the corresponding measurement of a male of _T. b. berlandieri_, No. 116466 from Camargo, Tamaulipas, in parentheses. The third measurement is that of the female from the type locality of _S. h. solus_ and it is followed by the corresponding measurement of a female of _T. b. berlandieri_, No. 116462 from Camargo, Tamaulipas. Total length, 266 (298),--(293); length of tail, 113 (135),--(137); length of head and body, 153 (163), 155 (156); length of hind foot, 30 (35), 30 (33); basilar length of Hensel, 28.2 (28.9); 27.9 (29.0); zygomatic breadth, 19.5 (--), 19.0 (20.8); mastoidal breadth, 13.9 (14.4), 13.9 (14.8); greatest breadth of rostrum, 7.2 (7.3), 7.8 (7.2); length of nasals, 14.6 (14.1), 13.4 (14.2); crown length of upper molar teeth, 6.3 (6.1), 6.3 (5.9). _Specimens examined._--Two from the type locality. Lepus californicus curti new subspecies Black-tailed Jack Rabbit _Type._--Female, adult, skull and skin, No. 35470, Mus. Nat. Hist., Univ. Kansas; from island, 88 miles south and 10 miles west of Matamoros, Tamaulipas, Mexico; obtained 19 March 1950 by E.R. Hall; original No. 6783. _Range._--Islands along coast of Tamaulipas, Mexico. _Diagnosis._--Color pale; size small; ears short; tympanic bullae small. _Comparisons._--From _Lepus californicus merriami_ Mearns (specimens from Fort Clark, Brownsville and intermediate localities), _L. c. curti_ differs in paler color, lesser size except ear that is of almost same length and except interorbital breadth that is approximately same in the two subspecies; tympanic bullae notably smaller. From _Lepus californicus altamirae_ Nelson, _L. c. curti_ differs in having the black patch on the nape less definitely divided by a median, longitudinal band of buffy color, and lesser size. Exception is to be made for the ear and tympanic bullae, which are of approximately the same size in the two subspecies. _Remarks._--The subspecific part of the name _Lepus californicus curti_ is proposed in honor of Dr. Curt von Wedel who shared the pleasure of collecting on the islands where this handsome hare lives.