850 HULLETIN 06, UNITED STATES NATIONAL MUSEUM. 



Genus CASTOR Linnaeus (1766). 



<\t.xl<>r l.iNN.Kis, Syst. Nat., ll'tli cmI., I76ti, I, ji. 7S. 



The upper inoliir te(^tli are siiheciual, each with one internal and 

 two external enaniel-t'olds; the stomach has a large glandular mass 

 situated to the right of the (esophageal orifice; the anal and urethro- 

 genital orifices open within a coninion cloaca; the tad is hroad, hori- 

 zontally flattened, and naked; and the hind feet ai"e webbed. {Flower 

 (did Li/del'lt-r. ) 



CASTOR CANADENSIS FRONDATOR Mearnr. 

 BROAD-TAILED BEAVER; SONORAN BEAVER. 



('aslor caiiatleiisis frondnhn- 'SIeahss, Proc. V. S. Nat. Musi., XX, p. 50o, Jan. 19, 

 lcS98, (advaiu-e sheet issued .Mar. 5, 1897; original ilescription. — Millkk and 

 RiciiN, Proc. Bost. Soc. Nat. Hist., XXX, No. 1, Dec. 27, 1901, p. 6:5 (Syst. 

 , Resnlt8 Study N. Am. Mam. to cloge of 1900). 



[CaMor canadi'iif<(s] frondator, Elliot, Field Col. Mns.,Zool. Ser., II, 1901, p. 1 IH 

 (Synop. Mam. N. Am.). 



Cuator rjjmadeusis] frondatur, Elliot, Field ('ol. Mu^^., Zool. Ser., I\', 1904, i){). 

 159 to 161, fig. 30 (skull of type); fig. 34 (animal). (Mam. Mid. Am. ). 



I'dli-hone-dh of the Hopi Indians. 



A])-?'-yi(i of the Hualapai Indians. 



Til p( -locality. — San Pedro River, Sonora, Mexico, near Monument 

 No. 98.— (Type, skin and skull, No. UUl, U. S. National Museum.) 



Geographical range. — This form occupies the southern interior area 

 of North America, ranging north from Mexico to Wyoming and Mon- 

 tana, its habitat being, of course, restricted to the vicinity of wooded 

 streams, which it follows through the Austral and Transition zones. 



Description. — Larger than the beaver of Canada, paler and different 

 in coloration, with a much broader tail. Above russet, changing to 

 chocolate on the caudal peduncle above, and to burnt sienna on the 

 feet; toes reddish chocolate. Below grayish cinnamon, brightening 

 to ferruginous on the under side of the caudal peduncle. Sides wood- 

 brown, enlivened by the tawny olive color of the overhair. Length, 

 1,070 mm.; length of tail, measured from anus, 360; length of bare 

 portion of tail, 125; height of ear from crown, 31 ; height of ear from 

 anterior base, 35; distance from tip of nose to eye, 68; from tip of 

 nose to ear, 125; nose to occiput, 165; length of manus, w^ith claw, 

 82; length of pes, with claw, 185. SkuH, 133 mm. by 99. Weight, 62 

 pounds avoirdupois. 



Cranial characters. — The skull of the European heaver ( Castor 

 fiber), w^hich is readily distinguishable from that of the Canadian 

 beaver (Castor canadensis) by its slender build, lengthened nasal 

 bones, and elongated rostral portion, presents still greater differences 



