Mammals 49 



the auditory ossicles, I have approached the problem of Muroid 

 classification from quite a different angle from that of Miller and 

 Gidley, and now reviewing the subject, would combine their 

 results with mine in a modified arrangement, as follows: 



( 1 ) Cricetidae, with subfamilies Cricetinae (Old World forms, 

 with no orbicular apophysis on the malleus, including Cricetus, 

 Cricetulus and Phodopus), Neotominae (wood rats), and Sigmodont- 

 inae (white-footed mice and many other genera of North and 

 South America) . 



(2) Arvicolidae (Microtidae), the voles and musk-rats. 



(3) Muridae, the mice and rats introduced from Europe. 

 Our Neotominae include the genus Neotoma of Say and Ord, 



originally based on an animal from Florida. We have two sub- 

 genera; true Neotoma, with the tail round, short-haired, smooth 

 and tapering, and Teonoma of Gray (an anagram of Neotoma) 

 with the tail large and bushy. Although these rats form numer- 

 ous local races, the range of the species, as generally understood, 

 is remarkable. Thus the original N. floridana of Ord, described 

 from Florida, has a race haileyi of Merriam, found at Wray, 

 Pueblo and Ft. Lyons in Colorado. It is a large rat, about 14 

 inches long, dark rusty brownish above in summer, creamy buff 

 or buffy grey in winter.* Goldman remarks** on the great differ- 

 ences between haileyi and floridana, but says that intermediate 

 races bridge the gap. N. mexicana of Baird, described from 

 Mexico, has a race fallax of Merriam, discovered at Gold Hill, 

 Colorado, by Denis Gale. This race is widely distributed in our 

 mountains, going down to 4,600 feet. It is about 13 inches long, 

 and is creamy buff or pale grayish above, darker over top of head 

 and back. N. albigula, known in various forms from California, 

 Arizona, and Mexico, has a race warreni of Merriam, found by 

 Warren in Baca County, and since obtained also at Clayton, New 

 Mexico. Warren describes it as gray above, lightly lined with 

 black; sides and cheeks rather ochraceous; tail black above, white 

 below. The characters of the skull cause it to be grouped with 

 N. albigula. N. micropus of Baird, described from Tamaulipas, 



*Mr. Warren writes that it comes up trie Fountain Valley more than 20 miles above 

 Pueblo, and is found in Chico Basin, and at Cedar Point, northwest of Limon. 



**Revision of the Wood Rats of the Genus Neotoma. North American Fauna No. 31 . 

 (1910). 



