24 Mvn'htm — Ecrtsion of fJic Coyotes. 



Cranial and denial characters. — Skull* and teeth, particular!}' the latter, 

 largest of the group; frontals flatter than in the other forms; premolars 

 very mucli swollen, particularly the lower ones; carnassial teeth very 

 thick and tumid. Tlie only Coyotes whose skulls approach C lahxais in 

 size are pallidus, lestes, frustror, and ochropus. The two latter may be dis- 

 missed at once on account of the great disparity in the teeth, the carnas- 

 sials anil premolars being hardly more than two-thirds as large as tiiose 

 of latraus. C. frustror differs furtlier in having the frontals more elevated 

 than in any other member of the group, while in C. latrans they are the 

 flattest and most depressed. Large male skulls of C. ocliropns sometimes 

 have the rostrum (measured from back of last molar to front of incisors) 

 of the same length as small males of la(ra)is, but the rostrum is always 

 very much narrower and the postpalatal part of the skull smaller. The 

 difference between latran.s and ochropus in size of teeth is very great, the 

 upper carnassial and first molar together measuring 35 millimeters in an 

 adult male lalratis, contrasted with oO in an adult male ochropus having 

 the entire tooth row of exactly the same length. In C. latrans the pre- 

 molars are so large that the tooth row is crowded, while in ochropus they 

 are widely spaced. The teeth of the female laira])s are decidedly larger 

 than those of the male ocliropus. 



The species having teeth sufficiently large to require comparison with 

 latrans are pallidus and lestes. In both of these the lateral teeth of the 

 male equal or exceed those of the female latrans. Comparing skulls of 

 the same sex, the upper carnassial and first molar and the premolars in 

 both jaws, particularly the lower, are larger, more swollen, and more 

 crowded in latrans. In latrans also the inner cusp {protocone) of the upper 

 carnassial averages decidedly larger than in either of the others. 



Mea-nirements. — Female young adult from Elk River, Minnesota: total 

 length, 1219; tail vertebrse, o94; hind foot (in dry skin), 179. 



Cranial measurements. ^(^ adult from Elk River, Minnesota: basal 

 length, 190; basilar length of Hensel, 186 ; zygomatic breadth, 109 ; pala- 

 tal length, 96; mastoid l>readth, 65; length of crown of upper carnassial 

 tooth, 22. The skull of an adult female from Elk River measures: basal 

 leiigtli, 175 ; basilar length of liensel, 172; zygomatic breadth, 100 ; pala- 

 tal length, 96; mastoid breadth, 62; length of crown of upper carnassial 

 tooth, 20.5. 



Canis pallidus sp. nov. 



Type locaidij. — Johnstown, Brown County, Nebraska. Type No. 77093, 

 cJ' young adult, U. S. National ]\Iuseum, Department of Agriculture col- 

 lection. Collected March 12, 189(5, by E. E. Fast. 



Clniracters. — Similar to C. hdrans. but everywhere jaaler; backs of ears 

 buff instead of fulvous ; skull and teeth smaller. 



C'o/or.— Muzzle dull ochraceous buff; top of head grizzled grayish fainily 

 tinged with bufi'; ears buft"; upper parts ])ale huffy whitish or soiled white 



* The skulls of C. latrans used in the present comparison are from Elk 

 River, Minnesota. 



