1915.] 



SCAPAifUS LATtMAiTUS GRIITNELLI. 



69 



length, 12.3; mastoidal breadth, 15.6; interorbital breadth, 7.1; 

 maxillary tooth row, 9.9; manidibular molar-premolar row, 9.4. 

 Skulls of 2 young adult females from Olancha, Cal. : Greatest length, 

 31, 31.5; palatilar length, 12.2, 12.6; mastoidal breadth, 15.1, 15.6; 

 interorbital breadth, 7.2, 7.3; maxillary tooth row, 9.9, 10; mandib- 

 ular molar-premolar row, 9.4, 9.6. 



Remarks. — ^The mole of southern CaUfornia is constant in charac- 

 ters over its entire range. The type of occultus is a young adult 

 female; it has abnormal mandibular teeth; the right first lower 

 premolar is absent, and the left first lower premolar is crowded back 

 and inward, close to the second premolar and in the same enlarged 

 socket with it. Specimens from Witch Creek are slightly larger 

 than those from the type region. Toward the northern border of 

 its range the subspecies shows a gradual increase in size until it 

 intergrades with S. I. latimanus in the region north of Santa Barbara 

 County. A young adult male from Tehachapi and a specimen from 

 Santa Barbara approach latimanus in size. A male from Porter- 

 ville, Tulare County, is larger and slightly darker than typical 

 specimens of occultus, and has a relatively narrower skull, probably 

 showing in these respects a tendency towards ^S'. I. sericatus. An 

 imperfect skeleton, with broken skull, from Sanger, Fresno County, 

 is provisionally referred to occultus; in dentition and in the size and 

 proportions of the mandible it is indistinguishable from specimens 

 from the type region. Two females from the south end of Owens 

 Lake are almost indistinguishable from typical occultus, their only 

 approach toward S. I. grinnelli being in slightly higher braincase. 

 The relationships of occultus with Scapanus antJionyi are not clear, 

 but the differences in size and color alone are sufficient to separate 

 the two forms, even though it should ultimately be proven that the 

 dentition of the type of anthonyi is abnormal (p. 76). 

 Specimens examined. — Total number, 73, as follows: 

 California: Alhambra, 10; Canyada Laga, 4 miles north of Ventura, 1;^ Comp- 

 ton, 21; Julian, 2;^ Los Angeles, 3; Olancha, 2; Pasadena, 2;^ Porterville, 1; 

 Eiverside, 1; San Bernardino, 5; San Bernardino Peak, 1; San Diego County, 

 5; San Gabriel, 1; Sanger, 1;^ San Jacinto Mountains, 2; 2 Santa Ana Canyon 

 (type locality), 1;^ Santa Barbara, 1; Sierra Madre, Los Angeles County, 1;^ 

 Somerset, 4; Tehachapi, 1; Ventura, 1;^ Warner Pass, San Diego County, l;^ 

 Witch Creek, 5. 



SCAPANUS LATIMANUS GRINNELLI Jackson. 



Grinnell's Mole. 



(PI. IV, fig. 6; PI. VI, fig 15.) 



Scapanus latimanus grinnelli Jackson, Proc. Biol. Soc. Washington, vol. 27, p. 56, 

 March 20, 1914. 



Type locality. — ^^Independence, Inyo County, California; altitude 

 3900 feet. 



1 Collection MUwaukee Public Mus. 



2 Collection Mus. Vert. Zool., Univ. California. 



