1. _M. f. noveboracensis_ 2. _M. f. occisor_ 3. _M. f. primulina_ 4. _M. f. arthuri_ 5. _M. f. olivacea_ 6. _M. f. peninsulae_ 7. _M. f. spadix_ 8. _M. f. longicauda_ 9. _M. f. oribasus_ 10. _M. f. alleni_ 11. _M. f. arizonensis_ 12. _M. f. nevadensis_ 13. _M. f. effera_ 14. _M. f. washingtoni_ 15. _M. f. saturata_ 16. _M. f. altifrontalis_ 17. _M. f. oregonensis_ 18. _M. f. munda_ 19. _M. f. xanthogenys_ 20. _M. f. nigriauris_ 21. _M. f. latirostra_ 22. _M. f. pulchra_ 23. _M. f. inyoensis_ 24. _M. f. neomexicana_ 25. _M. f. texensis_ 26. _M. f. frenata_ 27. _M. f. leucoparia_ 28. _M. f. perotae_ 29. _M. f. macrophonius_ 30. _M. f. goldmani_ 31. _M. f. tropicalis_ 32. _M. f. perda_ 33. _M. f. nicaraguae_ 34. _M. f. costaricensis_ 35. _M. f. panamensis_ 36. _M. f. meridana_ 37. _M. f. affinis_ 38. _M. f. aureoventris_ 39. _M. f. helleri_ 40. _M. f. macrura_ 41. _M. f. agilis_ 42. _M. f. boliviensis_ 43. _M. a. africana_ 44. _M. a. stolzmanni_ Hamilton (1933:328), however, writes that _M. f. noveboracensis_ is to "be found in pairs when caring for the young. During mid-May, 1927, I several times saw a male of this species carrying food to a den of young ones." Green (1936), in May in Gratiot County, Michigan, remarks that while he was uncovering and examining a nest of four young weasels, two adults ran about excitedly and one removed a young weasel. In instances where several nearly full-grown young have been obtained from one den it has been my experience (Hall, 1946:191) that the only adult trapped there was the female; no adult male was found or in the one instance when found he was living alone in a den 200 yards away from the den of the female and her young. Data are too few to warrant a definite conclusion about the extent to which the male aids in rearing the young, but I have wondered if he might not do so when the young were less than half grown and then live alone when they were more than half grown. =Mustela frenata noveboracensis= (Emmons) Long-tailed Weasel Plates 16, 17, 18, 31, 32 and 33 _Putorius Noveboracensis_ Emmons, Quadrupeds of Massachusetts, p. 45, 1840. _Mustela fusca_ DeKay, Zool. of New York, Pt. 1, Mammalia, p. 34, 1842. _Putorius fuscus_ Audubon and Bachman, Journ. Acad. Nat. Sci. Philadelphia, 8 (Pt. 2):288, 1842; Audubon and Bachman, Vivip. quadrupeds of N. Amer., 3:234, pl. 148, 1853 (pl. 1848). _Putorius noveboracensis_, DeKay, Zool. of New York, Pt. 1, Mammalia, p. 34, 1842; Baird, Mamm. N. Amer., p. 166, 1858; Merriam, N. Amer. Fauna, 11:16, pl. 4, figs. 1, 1a, 2, 2a, pl. 5, figs. 3, 3a, text figs. 4-6, 30, June 30, 1896; Bangs, Proc. Biol. Soc. Washington, 10:13, pl. 1, figs. 2, 2a, pl. 2, figs. 2, 2a, and pl. 3, figs. 3, 3a, February 25, 1896; Cory, Mamm. Illinois and Wisconsin, p. 366, plates, 1912.