PEROMYSCUS. 175 



PAGE 



q.' Above fulvous brown P. z. cristobalcnsis 209 



r.' Rostrum elongated, bullae small. 



a." Above fulvous chestnut and black P. megalops 210 



b." Smaller and darker. 



a/" Tail unicolor P. melanocarpus 210 



b/" Tail with white line beneath P. altilaneus 210 



c." Above blackish gray P. guatemalensis 211 



d." Above sooty brown P. cacabatus 211 



b. Tail nearly two-thirds the length of head and 



body. Ears large P. mecisturus 212 



127. tiburonensis (Pe romyscus) , Mearns, Proc. U. S. Nat. Mus., 



1897, P- 7 20 - 

 ISLAND OF TIBURON MOUSE. 



Type locality. Tiburon Island, Gulf of California, Mexico. 



Geogr. Distr. Known only from type locality. 



Genl. Char. Size very small; ears nearly naked. 



Color. Upper parts drab gray and black; sides ochraceous cin- 

 namon; under parts white; tail blackish brown; hands and feet 

 white; ears dark brown. 



Measurements. Total length, 175; tail vertebrae, 85; hind foot, 

 19; ear, 16. Skull: total length, 24; greatest width, 12. (Mearns, 

 I.e.) 



*127a. allex (Peromyscus} , Osgood, Proc. Biol. Soc. Wash., xvn, 



1904, p. 76. 

 DWARF MOUSE. 



Type locality. Colima, State of Colima, Mexico. 



Genl. Char. Like P. musculus, but smaller; nasals short; bullae 

 very small. 



Color. Exactly like P. musculus. 



Measurements. Total length, 113; tail vertebrae, 47; hind foot, 

 14; ear from notch, 9.7. Skull: greatest length, 18.4; Hensel, 14.6; 

 zygomatic width, 9.6; interorbital constriction, 3.2; length of nasals, 

 6.3; interparietal, 5.5 X 1.3; palate, 3; length of upper molar series, 3. 



128. musculus (Sitomys), Merr., Proc. Biol. Soc. Wash., vm, 1892, 



p. 170. 

 COLIMA CITY MOUSE. 



Type locality. Near Colima City, State of Colima, Mexico. 

 Geogr. Distr. States of Colima and Jalisco, Mexico. 

 Genl. Char. Similar to P. taylori, but lighter and larger. 



*Descriptions of numerous forms of Peromyscus by Mr. Osgood (1. c.) were 

 published too late to be included here in their regular numerical order. 



