400 



MULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



PEROMYSCUS SONORIENSIS CLEMENTIS (Mearns). 

 SAN CLEMENTE MOUSE. 



Peromyscus texanus dementis Mearns, Proc. U. S. Nat. Mus., XVIII, 1896, pp. 446, 

 447 (p. 4 of advance sheet issued March 25, 1896; original description). — Miller 

 and Rehn, Proc, Bost. Soc. Nat, Hist., XXX, No. 1, Dec, 27, 1901, p. 84 (Syst. 

 Results Study N. Am. Mam. to close of 1900). 



[Peromyscus texensis] dementis , Elliot, Field Col. Mus., Zool. Ser., II, 1901, p. 130 

 (Synop. Mam. N. Am.); IV, 1904, p. 187 (Mam. Mid. Am.). 



Type-locality. — San Clemente Island, off southern California. (Type, 

 skin and skull, Cat. No. 61117, U. S. National Museum.) 



Geographical range. — Islands of the Santa Barbara group, southern 

 California, and the Coronados Islands, off Lower California. 



This insular mouse was described as a subspecies of the mainland 



form for the reason that examples from the nearer islands seemed 



to be somewhat intermediate in character between the typical form 



on San Clemente Island and that of the coast. The species occurs 



on each of the Coronados Islands and on several 



islands of the Santa Barbara group. 



Description. — This mouse is considerably larger and 

 much blacker than P. s. medius of the neighboring 

 mainland, and has a more pronounced reddish tinge. 

 The upper surface is drab anteriorly, strongly tinged 

 with burnt umber posteriorly; top of head drab-gray; 

 ears black, with faint hoary edging; feet and under 

 surface white; tail sharply bicolored, blackish above. 

 The above description is based on a series of specimens 

 taken by the author in August, 1894. Mr. A. W. 

 Anthony, the well-known naturalist of San Diego, col- 

 lected a series at the same time, which lie kindly 

 placed at my disposal. The skull (fig. 78) of this island 

 race, while almost as large as that of P. s. deserticola from the lower 

 Colorado River, is more slender and fragile. Iris dark hazel. 



Habits and local distribution. — This appears to be the only mouse 

 on San Clemente Island, where it is exceedingly abundant, living 

 on sandy shores amongst the cactus and in ravines under such shrubs 

 as the Christmas berry, cherry, and sumach. It feeds on the ripe 

 fruit of the prickly pear, Opuntia {Platopuntia) lindheimeri littoralis, 

 which stains its pelage. About 40 specimens were taken by Mr. 

 A. W. Anthony and myself. Similar mice were said to abound on 

 the Coronados Islands, south of the International Boundary. 



Fig. 78.— Peromy- 

 scus SONORIEN- 

 sis clementis. 

 Skull. 



