CRANIAL VARIATION IN MEPHITIS MEPHITICA. 207 



Maine aud Massachusetts, and one from Kortheastern New 

 York ; three are from Pennsylvania ; and of the remaining five, 

 four are from Texas, and one from Louisiana. The western 

 series of ten average 3.10 in length and 1.95 in width, ranging 

 in length from 2.85 to 3.50 and in width from 1.70 to 2.25. Tiie 

 New England series of ten average 2.88 in length and 1.72 in 

 width, ranging in length from 2.70 to 3.25 and in width from 

 1.53 to 1.85. The single New York specimen scarcely varies 

 from the average of the New England series, while the Penn- 

 sylvania specimens fall a little below. The five southern speci- 

 mens average 2.73 in length, or a little below the New England 

 series, ranging in length from 2.60 to 2.90.* 



'' It thus appears that the western specimens are decidedly 

 the largest of all, and that the northern are somewhat larger 

 than the southern, the specimens compared being of correspond- 

 ing ages, though of unknown sex, but doubtless comparable in 

 this respect also. 



*'The difference in size amounts to above one-fourth the size 

 of the largest specimen and above one-third the size of the 

 smallest. Between the western and southern series, the aver- 

 age difference amounts to one- third of the average size of the 

 larger series! The western series includes the so-called Me- 

 phitis occidentalis of Baird, based on California specimens, and 

 whose chief difference is merely that of larger size; yet the 

 four specimens from Ogden, Utah (Goll.Mus. Comp. Zool.), con- 

 siderably excelled in size the three from California. The south- 

 ern series represents the so-called if. varians of Gray and Baird. 



"The unsatisfactory character of the several species of North 

 American Skunks of the mephitica group, and the wide range 

 of color-variation among individuals from the same locality, I 

 have previously had occasion to notice, t and a re-examination 

 of the subject confirms the conclusions then announced, which, 

 I am happy to find, have recently received the support of Dr. 

 Coues, who has lately made a study of this group.f As Dr. 

 Coues has remarked, and as the subjoined measurements show, 

 few species of animals vary so much in size and in cranial char- 

 acters as the present, independently even of sex and age. Some 



* " The range in width is not fairly indicated, owing to two of the smaller 

 specimens being imperfect." 

 + " See Bull. Mus. Comp. Zool. vol. i. pp. 178-181, Oct. 1869." 

 t " Bull. U. S. Geol. and Geog. Surv. of the Territories, vol. i. no. 1, pp. 7-15, 



1875." 



