DESCRIPTION OF A NEW KANGAROO RAT FROM 



LOWER CALIFORNIA (DIPODOMYS MERRIAMI 



MELANURUS subsp. nov.) COLLECTED BY 



WALTER E. BRYANT. 



BY C. HART MERRIAM. 



In an interesting collection of mammals from the Cape 

 region of Lower California, sent me for examination by 

 Mr. Walter E. Bryant, is an undescribed kangaroo rat 

 which Mr. Bryant has kindly asked me to name. 



It is a small 4-toed form closely related to Dipodomys 

 merriami Mearns (from New River, Arizona), with 

 which it doubtless intergrades and from which it dif- 

 fers chiefly in having the terminal third of the tail 

 abruptly blackish. The very large series of D. merriami 

 in the U. S. Department of Agriculture collection (com- 

 prising upwards of 600 specimens) shows that the distal 

 part of the tail becomes darker in passing southward from 

 Arizona and southern California through Sonora, and 

 that specimens from Ortiz and Guaymas are almost ident- 

 ical with those from the Cape region of the peninsula. 



The new form may be known from the following de- 

 scription: 



Dipodomys merriami melanurus subsp. nov. 



Type No. 539 5 ad. Collection of California Academy 

 of Sciences. From San Jose del Cabo, Lower Califor- 

 nia, March 19, 1892. Collected by Walter E. Bryant. 

 Original number, 551. 



Measurements of type (taken in flesh by collector). — 

 Total length, 239; tail vertebrae, 144; hind foot, 35. 

 Average measurements of six specimens from type local- 



2d Ser., Vol. III. June 5, 1893. 



