None of the skulls examined shows malformation of the frontal sinuses such as results from infestation by parasites in some races. Arthur (1928:115) speaks of the ". . . cut-over swamp land, where the tupelo and cypress have been removed, . . ." as constituting suitable habitat for this animal. _Specimens examined._--Total number, 13, as follows: =Texas.= _Colorado County_: 12 mi. N Eagle Lake, 1[43]; 5 mi. W Eagle Lake, 1[43]; 3 mi. S Garwood, 1[43]. =Louisiana.= _East Baton Rouge Parish_: Baton Rouge, 4[71]. _Livingston Parish_: Springville, 1[74]. _Saint James Parish_: Convent, 1[91]; Remy, 2 (1[74], 1[45]). _Assumption Parish_: near Lake Verret, 1[45]. =Mississippi.= _Harrison County_: Saucier, 1[71]. =Mustela frenata olivacea= Howell Long-tailed Weasel Plates 16, 17, 18, 31, 32 and 33 _Mustela peninsulae olivacea_ Howell, Proc. Biol. Soc. Washington, 26:139, May 21, 1913. _Mustela frenata olivacea_, Hall, Carnegie Instit. Washington Publ. 473:104, November 20, 1936. _Type._--Male, adult, skull and skin; no. 180802, U. S. Nat. Mus., Biol. Surveys Coll.; Autaugaville, Autauga County, Alabama; December 22, 1912; obtained by L. S. Golsan. The skull (plates 16-18), although cracked at two places in the interorbital region, is in one piece and not warped out of shape. The teeth all are present and entire. The skin is exceptionally well made and in perfect condition except for the extreme tip of the tail which is broken off. _Range._--Lower and Upper Austral life-zones in eastern Mississippi, Alabama, Georgia, South Carolina, and northern Florida. See figure 29 on page 221. _Characters for ready recognition._--Differs from _M. f. peninsulae_ in finer, softer pelage and shorter (less than 15.8 in ad. [F]) tympanic bullae; from _M. f. noveboracensis_, in adult males by wider tympanic bulla which is more than rather than less than 8.5, in adult females by total length which is more than rather than less than 345, and by mastoid breadth which is more than rather than less than distance between articular faces of exoccipital condyle and glenoid fossa; from _M. f. arthuri_ in larger size (adult males with hind foot and basilar length each more than 45); depth of skull at anterior margin of basioccipital, ignoring sagittal crest, amounting to less than 63 per cent of mastoid breadth, and lesser convexity of dorsal outline of skull in longitudinal axis (See pls. 16-18). _Description._--_Size._--Male and female: External measurements of adults are available as follows: