1900] Zoological Notes. 173 



ZOOLOGICAL NOTES. 



A Canadian Pocket Mouse — [Perognathus Lordi, Gray). 

 Under the direction of Dr. C. Hart Merriam, Chief of Division 

 of Biological Survey of the United States Department of Agricul- 

 ture, (one of the corresponding members of the Ottawa Field- 

 Naturalists' Club,) Mr. Wilfred H. Osgood, Assistant Biologist, 

 has prepared a " Revision of the Pocket Mice of the Genus Pero- 

 gnathus," just issued at the Government Printing Office in Wash- 

 ington, and forms Bulletin No. 18 of the " North American 

 Fauna," a series of peculiar interest to all naturalists. 



Upwards of 3,000 specimens have been examined in the 

 course of preparation of this monograph. The progress made up 

 to date in researches concerning the interesting group of the 

 HeteromyidEe, one of the most peculiar groups of New World 

 mammals, is therein given. 



Besides Perognathus, the other genera of the Pocket Mice 

 are : Heteromys, Dipodomys, Perodipus and Micropodops. 



Perognathus is divisible into two sub-genera : Perognathus 

 proper, and Chcetodipus, the latter containing the large coarse- 

 haired and long-tailed " forms," whilst Perognathus includes the 

 small soft-haired species. 



Of the forms described, Perognathus Lordi, Gray, is recorded 

 from British Columbia, the type locality, as a member of the 

 ** Parvus" group, i.e., of the group of Perognathus parvus (Peale). 

 Mr. Osgoode thus describes this little animal : 



^^Ge7ieral characters. Similar to P. parvus; size, large (nearly 

 equalling Magruderensis ; tail, long ; feet and ears, moderate ; 

 antifragus, lobed ; color, dark ; interparietal, narrow 



'■'■Color. Above, pale slatey buff, strongly mixed with black ; 

 general color as in the gray phase of P. parvus; hairs of belly 

 generally with plumbeous bases and buffy tips, leaving a small 

 marginal and a large pectoral patch pure white; sub-auricular spot 

 small but distinct; tail tricolor as in P. parvus. 



'^ Skull. Size large and audital bullae and mastoids inflated ; 

 andital bullae always connected anteriorly ; interparietal, squarish 

 pentagonal, deeply notched by occipital. 



"Measurements. Average of seven adults from Oroville, 

 Wash. : Total length, 183 ; tail vertebrae, 97.7 ; hind foot, 23.2 ; 

 skull, basilar length of Hansel, 16,5 mm.; occipito-nasal length, 

 23 mm.; greatest mastoid breadth, 1 1.8 mm.; greatest width of 

 interparietal, 4.3 mm. 



