PROCEEDINGS OF THE NATIONAL MUSEUM. 561 



the sides and posterior portion of the back where the winter hair has 

 fallen out en masse and is being- replaced. The ventral surface is still 

 covered with dense, long hair. The difference between the coloring of 

 the winter and summer coats is slight. 



Another specimen (ISTo. Iffll, IT.S.ISr.M.), an adult female containing 

 three small fetuses, taken at the same locality June 10, 1892, is quite 

 similar to the type in coloring, but has acquired the short summer 

 coating on the whole ventral surface, though the change has not pro- 

 gressed as far on the dorsum, shedding having taken place only on the 

 head and nai)e, a few scattered patches anteriorly,' and over a large 

 area of the posterior border of the blanketed portion of the back, and 

 in the median area of the rump, to the tail. 



Another adult female (No. |§||-fj U.S.N.M.), taken at the same place 

 June 29, 1892, has only shed the winter hair on the chest and anterior 

 portion of abdomen, on the nose, and a few insignificant spots scattered 

 over the upper surface. It is therefore in nearly complete winter dress. 

 Though faded, the coloring is quite similar to the others. In these three 

 the feet are remarkably shorter-haired, all of the claws being exi^osed. 

 In comparison with the te.vianus group, the coat is short and coarse. 



Description of young. — Two young females (Nos. |ff§-§ and IfffI, 

 U.S.N.M.), from the same locality, June 16 and 17, 1892, are still in 

 the soft, woolly coat of early life, except on the front of the head and 

 anterior i)ortion of the middle of the back, where the coarser coating 

 has recently been acquired. This new pelage is vinaceous buff, that of 

 the rest of the upper surface of the body varying from cream buff to 

 cinnamon in different parts. The crown of the head is cinnamon ; its 

 sides clayey buff, except the orbital stripe, which is cream buff, and the 

 gular area buff. The upper side of the tail is black, considerably griz- 

 zled, and mixed with yellowish white, and the central stripe of the rump 

 is but faintly indicated. These two specimens, and an older one (No. 

 58911, U.S.N.M.), taken September 15, 1893, exhibit a very interesting 

 character of this species, which I have deferred mentioning until now 

 on account of the unsatisfactory condition of the pelage of the parts 

 in the adults above described, in which the sides have a more or less 

 patchy mixture of the winter and summer coats, tending to obscure 

 the pattern. This character consists of a light stripe of cream buff 

 extending along the anterior t^othirds of the body, above and par- 

 allel to the lower edge of the dark area of the back, spreading out 

 anteriorly and involving the shoulder. These stripes are analogous to 

 the shoulder stripes of SpcrmopliUns heecheyi; and, their presence having 

 been once determined in the present species, it is i)ossible to discover 

 traces of them in several other hares of this group. The importance 

 of this mark consists in its indication of the common ancestry of the 

 jackrabbits and cottontails. 



Dimensions. — Measurements of one adult male: Total length. 530 

 mm. ,• tail vertebr.p, 77 ; ear from crown, 140; ear from notch, 123; length 

 Proc. N. M. 95- — 36 



