160 NORTH AMERICAN MUSTELID^. 



entrance, into which the antecedent i^remolar is set. Moreover, 

 the autero-internal process, instead of being a mere heel or spur 

 standing off from the tooth, as in the other subgenera here 

 compared, develops into a strong, conical, acute cusp, some- 

 times with two points. The back lower molar, contrary to what 

 might have been expected, is absolutely not larger than that of 

 F.fa'tidus,* and therefore smaller relatively to the general de- 

 velopment of the teeth. The anterior lower molar (sectorial 

 tooth) develops on the inner side a slight but unmistakable 

 supplementary tubercle, like that so evident in 31ustela, but 

 smaller • the other species of Ptitorius which I have examined 

 have no trace of this lobe, or a mere rudiment. And, in gen- 

 eral, it may be said of the molars and premolars of Lutreola, 

 that their various cusps are better developed than in most, if 

 not all, other sections of Putorius. 



The details of external form of Lutreola are so fully given 

 beyond in the description of L. vison that they may be here 

 omitted. There is but one species known to inhabit North 

 America, very closely related to the Mink of Europe. The al- 

 leged differences between the two are presented further on, in 

 concluding a discussion of their affinities. 



The Aiiiericaii ITIink. 



Patorias (liUtreola) vison. 



Plate IX. 

 Mustela vison, Briss. Quad. 175G, 246, no. 6 (from Canadian specimen, same as described by 



Buflfon and Penn3Lpt).—Schreb. Sang. iii. 1778, 463, pi. 127 b.—Gm. S. N. i. 1738, 94.— Turf. 



S. X. i. 1606, 58.— Ouv. R. A. i. 1817, 150.— Harl. Fn. Amer. 1825, 63.— Less. Man. 1827, 



148.— J/^a;im. Reise, i. 1839, 'ZlZ.-Blainv. Osteogr. Mustela, pi. 13 (teeth).— TAornps. 



K. H. Verm. 1853, 31. 

 Mustela (Martes) vison, Desm. Mamm. i. 1820, 183.— Griff. Cuv. R. A. v. 1827, 124. 

 Muslela (Putorius) vison, Jiich. F. B.-A. i. 1829, 48, no. 16. 

 Mustela (lutreola) vison, Wagn. Suppl. Schreb. ii. 1841, 241. 

 lutra vison, Shaiv, Gen. Zool. i. 1800, 448 (based on the Vison of Buffon). 

 Putorius vison, Gapp. Zool. Journ. v. 1830, 202.— Etmnons, Rep. Quad. Mass. 1840, i3.—De K. 



N. V. Z. i. 1842, 37, pi. 11, f. 1 (animal), pi. 8, f. 3, A, B (skull).— And. <£ Bach. Q. N. A. i. 



1849, 250, pi. 33.— iie/in. Tr. 111. State Agric. Soc. for 1858-4, 1855, 518.—B€esley,Geo\. 



Cape May, 1857, \31.—Baird. M. N. A. 1857, 177, pi. 37, f. 2, 3 (skulls).— A^eu^i. P. R. R. 



Rep. vi. 1357, A^.-Coop. <& Suckl. N. H. W. T. 1860, 93, 115.— Billings, Canad. Nat. and 



Geol. ii. 185f, 4i8.—I{oss, op. cit. vi. 1861, 29.— Maxim. Verz. Am. Saug. 1862, 52.— 



Sam. Am. Rep. Mass. Agric. for 1861, 1802, 157, pi. 1, f. 8.— Gilpin, Tr. X. Scotia Inst. 



ii. 1870, 12, 59.— Am^, Bull. Minn. Acad- Xat. Sci. 1874, 69.— Ooues <£ Tarroiv,Zo'6l. 



Expl. W. 100 Merid. v. 1875, 60.— Allen, Bull. U. S. Geol. Sur. vol. ii. no. 4, 1876,326 



(skull). 

 Mustela lutreola, Forst. Phil. Trans. Ixii. 1772, 371.— ^a?>. Frank. Journ. 1823, 652.— Fisch. 



Syn. 1829, 221 (partly).— (?odj?i. Am. Xat. Hist. i. 1831, 206.— Hall, Canad. Nat. & 



Geol. vi. 1861, 295. 



* As elsewhere stated, in Cynomyonax this tooth is singularly minute. 



