Intergradation with Mustela frenata spadix is indicated by subadult males from western Wisconsin, namely, one from Gordon, three from Colfax and one from Meridean. Linear measurements of the teeth of these specimens are exactly intermediate between those of spadix from Elk River, Minnesota, to the west, and noveboracensis from, say, Beaver Dam, Wisconsin, to the east. The specimens from western Wisconsin show approach to spadix also in that the length of the tooth-rows and breadth of the rostrum are slightly greater than in noveboracensis from farther east, say, Beaver Dam, Wisconsin.
Indeed, animals from as far east as Beaver Dam itself might be thought of as showing some approach to spadix. Although, along the eastern seaboard, the upper lips, with rare exceptions, are the same color as the underparts, farther west, in Michigan and Wisconsin, the lips more often than not are white. Animals from Beaver Dam have slightly shorter black tips on the tails, broader extent of the light color of the underparts and females average slightly larger than typical noveboracensis, say, those from Massachusetts. Each of these differences reflects characters found better developed in the spadix-longicauda stock to the west.
Toward the southern part of its range where noveboracensis meets M. f. olivacea there is a marked increase in yellowness of the underparts. This coloration of the underparts, since it is not so well marked in the northern part of the range of noveboracensis, might be regarded as showing intergradation with olivacea and primulina, each of which has far more intensely colored underparts than does noveboracensis. Excepting this increase of yellow on the underparts, however, there are few if any characters of noveboracensis which undergo marked change as approach to the range of olivacea is made. Indeed, the characters of noveboracensis remain constant to within a relatively short distance of the geographic range of olivacea.
Notwithstanding the state of affairs described above, intergradation seems to take place. Three specimens referred to noveboracensis but which at the same time are regarded as intergrades with olivacea are as follows: No. 28.300, Charleston Museum, from five miles east of York, South Carolina, is an adult female with a badly crushed skull. In external measurements the specimen agrees with noveboracensis. The underparts, as regards color and width, are intermediate. The general proportions of the skull and tympanic bullae agree with those of noveboracensis but the skull is larger than in any female of true noveboracensis and approaches that of olivacea. The same can be said of a young female, no. 80, Ohio State Museum, from Roswell, Georgia.
Another female, no. 171559, U. S. Nat. Mus., from Lookout Mountain, 1500 ft., Fort Payne, Alabama, is barely subadult. The external measurements are nearer those of olivacea. The color and narrowness of the underparts are typical of noveboracensis. The proportions and especially size of the skull show approach to olivacea, though they are nearer to noveboracensis when all features are taken into account. In the northern part of its range individuals of noveboracensis attain larger size than farther south. This tendency reaches its extreme, in males at least, in M. f. occisor of Maine. Specimens of noveboracensis from the Adirondacks of New York average larger (see cranial measurements on page [418]) than those from farther south, and thus approach occisor in size as well as in geographic position. Also, occasional individuals which strongly show characters of occisor are found even farther south than the Adirondacks of New York. This is true of no. 96518, U. S. Nat. Mus., ♂ ad., from Lunenburg; Massachusetts. The animal has a large skull of relatively great width much as in occisor, although its external measurements, relative length of tail and long, terminal, black brush place it with noveboracensis rather than with occisor. Of a pair of specimens from Ossipee, New Hampshire, the male, no. 77108, U. S. Nat. Mus., has a long (175 mm.) tail, and short (60 mm.) black pencil as in occisor, although otherwise it is referable to noveboracensis. Still another specimen, a subadult male, no. 4193, Mus. Comp. Zoöl., from Upton, Maine, has a longer (51 mm.) hind foot than noveboracensis although it otherwise agrees with that subspecies. As remarked by Bangs (1899:55), other than fully adult specimens from the range of occisor are "troublesome," and would not be selected as distinct from noveboracensis if placed in a series of that subspecies, say, from New York State. In view of the facts that several specimens from intermediate localities combine the characters of noveboracensis and occisor, that noveboracensis in the northern part of its range averages larger than it does farther south and thus approaches occisor in size, and that occasional large specimens resembling occisor in several, but not all, features sometimes crop up in the northern part of the range of noveboracensis, it appears that noveboracensis and occisor intergrade. Therefore they are treated as two subspecies of the single species, Mustela frenata.
Intergradation with M. f. primulina has been commented on in the discussion of that subspecies. Female, no. 159980, U. S. Nat. Mus., from Golconda, Illinois, has many characters of primulina but two young males from there agree better with noveboracensis.
Examination of 283 adult and subadult skulls for malformation of the frontal sinuses revealed only ten that were not obviously malformed. Two were from New York, one from Massachusetts, one from Pennsylvania, and six from the 52 specimens from Michigan and Wisconsin. In addition, skulls of many young and even juveniles were malformed.
Specimens examined.—Total number, 555, arranged alphabetically by states and provinces and, unless otherwise noted, from north to south by counties in each state. Except as otherwise noted specimens are in the United States National Museum.
Alabama. DeKalb County: Fort Payne, 1.
Connecticut. Litchfield County: Riverton, 1[5]; Gaylordsville, 1. Hartford County: East Hartford, 4 (3[5]); Glastonbury, 2[5]; South Glastonbury, 4[5]. Windham County: Plainfield, 2 (1[14]). Fairfield County: Greenwich, 2[2]. New London County: Liberty Hill, 35 (33[75], 2[7]).
District of Columbia. Washington, 3; near Washington, 1; Eastern Branch, 1; Congress Heights, 1; Benning, 1; no definite locality, 1.
Georgia. Towns County: Young Harris, 1. Cherokee County: Canton, 1. Cobb County: Roswell, 1[81].
Indiana. St. Joseph County: Notre Dame, 2[99]. Porter County: Hebron, 1. Miami County: Denver, 5 (4[75], 1[4]). Wells County: Bluffton, 1. Howard County: Russiaville, 1. Jay County: Salamonia, 1[2]. Boone County, 1[2]. Knox County: Bicknell, 3.
Illinois. Lake County: Camp Logan, 3[60]; Fort Sheridan, 1[60]. Cook County: W Northfield, 2; Flossmoor, 1[60]; no locality more definite than county, 1. Du Page County: Bloomingdale Spg., 1[60]. Carroll County: Savanna, 1[87]. McLean County: Normal, 1[7]. Champaign County: Harwood Township, 1[7]. Pike County?: Milton Spring, 1[60]. Pope County: Golconda, 3.
Kentucky. Woodford County: Midway, 1. Hancock County: Hawesville, 1.
Maine. Oxford County: Upton, 1[75]; Bethel, 1[74].
Maryland. Howard County: Long Corner, 1; Hanover, 1. Montgomery County: Gaithersburg, 1; Garret Park, 1; Chevy Chase, 1; Bethesda, 1. Prince Georges County: Laurel, 18; Plummer Island, 3; Oxon Hill, 1. Talbot County: Easton, 1. Dorchester County: Cambridge, 5[40].
Massachusetts. Middlesex County: Wilmington, 6; Burlington, 6; Lexington, 1[75]; Wayland, 2[75]. Berkshire County: New Marlboro, 1[5]. Worcester County: Lunenburg, 2; Lancaster, 1[75]; Princeton, 2[75]. Norfolk County: So. Weymouth, 1[75]. Plymouth County: Wareham, 5[75].
Michigan. Marquette County: Michigamme, 1. Charlevoix County: Thumb Lake, 1[76]; 1/2 mi. N Thumb Lake, 1[76]. Leelanau County: Leland, 3[76]; Duck Lake, 2 mi. S Leland, 1[76]; Lost Pond, 8-1/2 mi. S Leland, 1[76]. Osceola County: Le Roy, 2[76]. Huron County: Rush Lake, 1[76]. Saginaw County: East Saginaw, 1. Oakland County: Royal Oak, 4[76]; South Lyon, 1[76]. Livingston County: Portage Lake, 1[76]. Washtenaw County: Portage Lake, 6[76]; Waterloo, 2[14]; Lima, 1[76]; Ann Arbor, 11[76]; 3 mi. E Ann Arbor, 1[76]; 2 mi. SE Ann Arbor, 1[76]; 2 mi. S Ann Arbor, 1[76]; 3 mi. S Ann Arbor, 1[76]; Dixboro, 1[76]; Pittsfield, 3 (2[76]); Saline, 1[76]; near Saline, 2[76]; 1 mi. S Saline, 2[76]; York, 2[76]; Manchester, 2[76]. Lenawee County: Morenci, 1[76]. Cass County: Marcellus Township, 1[76]. Berrien County: Harbert, 1[76]; Warren Wood Preserve, 1[76]; Warren Woods, 1[76].
New Hampshire. Grafton County: Franconia, 1[2]. Carroll County: South Chatham, 4 (3[5]); Ossipee, 2; Intervale, 1[5]. Merrimack County: Webster, 2[75].
New Jersey. Morris County: Morristown, 1. Essex County: West Orange, 1[2]. Mercer County: Princeton, 1[1]. Ocean County: Point Pleasant, 1[2]. Camden County: Haddonfield, 1[1]. Cumberland County: Millville, 2[74].
New York. St. Lawrence County: Ogdensburg, 1[74]. Clinton County: Rouses Point, 1[80]. County?: Adirondacks, 12. Essex County: Elizabethtown, 1; Schroon Lake, 1; no locality more definite than county, 1. Lewis? County: Locust Grove, 4; Lyons Falls, 1. Warren County: Lake George, 6; Caldwell, 1. Hamilton County: Beaver Brook, 1/2 mi. above mouth Indian Lake, 1[80]. Oswego County: Scriba, 2[74]; Palermo, 1[74]. Monroe County: Penfield, 3. Madison County: Peterboro, 6 (2[75]). Schoharie County: Schoharie, 1[2]. Rensselaer County: East Shodack, 1[80]. Tompkins County: Taughannock Falls, 2[58]; Ithaca, 4 (3[58]); Glenside, Ithaca, 1[58]; 6 mi. Creek, Ithaca, 1[58]. Green County: Lanesville, 1[2]. Orange County: Poplopen's Pond, 1[2]; Highland Falls, 1[2]. Putnam County, 1[19]. Westchester County: Sing Sing, 4; Armonk, 1[2]; Hastings, 3 (2[2], 1[19]). Nassau County: Flushing Meadows, 1[2]; Flushing, 1[58]; near Flushing, 1[2]; Oyster Bay, 2. Long Island: Cold Spring Harbor, 1; Bridgehampton, 1[2]. County in question: Severance, 3; Lake Grove (Long Island?), 1.
North Carolina (east to west by counties). Wake County: Raleigh, 4 (1[2], 1[75], 2[76]). Mitchell County: Magnetic City, foot of Roan Mountain, 6; Roan Mt., 1; Roan Mt., 6000 ft., 3. Buncombe County?: Valley of Black Mts., 1[2]. Madison County, 2[11].
Ohio. Trumbull County: Warren, 1[93]. Seneca County: Tiffin, 1[81]. Summit County: Ira, 2[81]. Crawford County: Galion, 1[81]. Ashland County: Loudonville, 1[76]. Auglaize County: New Bremen, 3[81]. Franklin County: 3 mi. N Columbus, 1[81]; Minerva Park, Columbus, 5[81]. Fairfield County: Sec. 32, Pleasant Twp., 1[81]; Lancaster, 1[81]. Clinton County: Reesville, 1; 1/2 mi. S and 1/2 mi. W Wilmington, 2[74]. Pike County: Waverly, 1[81].
Ontario. Sudbury District: Metagama, 2[86]. Carleton County: Ottawa, 2[77]. Muskoka County: Lake of Bays, 1; Bracebridge, 1. Haliburton County: Gooderham, 1[60]. Simcoe County: Orillia, 4 (2[2], 2[60].) Prince Edward County: Bloomfield, 1[77]. York County: Toronto, 1[2]. Waterloo County: Branchton, 3[60]; Preston, 2[77]; no locality save county, 1[60]. Welland County: Ridgway, 1[14]. Elgin County: St. Thomas, 1[77]. Essex County: Kingsville, 1[77]; Point Pelee, 1[77].
Pennsylvania (east to west by counties). Crawford County: Pymatuning Swamp, 3-1/2 mi. W Linesville, 1[9]; Meadville, 2[9]. Beaver County: Beaver, 1[9]; Raccoon Creek, 1[9]. Butler County: Mars, 1[9]; Leasuresville, 4[9]. Allegheny County: Allegheny, 1. Warren County: Bear Lake, 2[9]. Westmoreland County: Kingston, 1[9]; Laughlinstown, 2[9]. Somerset County: Confluence, 1[9]; Tub Mill Run, 2 mi. N Springs, 1[9]. Jefferson County: Siegel, 1[9]. Clearfield? County: Penfield, 1[9]. Cambria County: Cresson, 1[9]. Fulton County: Well's Tannery, 1[9]. Clinton County: near Round Island, 2[1]. Cumberland County: Carlisle, 1. Snyder County: 5 mi. S Selinsgrove, 1. Northumberland County: Pottsgrove, 1. Union County: Mifflinburg, 1. Sullivan County: Lopez, 7 (4[1], 3[74]). Chester County: Westtown, 1[1]; Valley Forge, 1[1]; W Bradford Township, 1[1]; no locality more definite than county, 3. Philadelphia County: Holmsburg, 2[1]. Bucks County: 1[1]. Pike County: Milford, 1.
Rhode Island. Providence County: Chepachet, 1. Washington County: Lake Warden, 2.
Quebec. Megantic County: Black Lake 1[77]. County in question: Meach Lake, 1[77].
South Carolina. York County: 5 mi. E York, 1[11]. Laurens County: Laurens, 1[39].
Tennessee. Campbell County: Highcliff, 1. Carter? County: Roan Mts., 1[2]. Hamilton County: Walden Ridge, near Soddy, 3.
Vermont. Windsor County: Hartland, 1[2].
Virginia. Shenandoah County: Toms Brook, 1. Arlington County: Arlington, 1; Ballston, 1; Alexandria, 1. Fairfax County: Falls Church, 3; Mt. Vernon, 2; no locality more definite than county, 1. Prince William County: Occoquan, 1. Essex County: Montague, 1. Prince George County, 1. Norfolk County: Wallaceton, 1. Grayson County: Mt Rogers, 3. County in question: Dismal Swamp, 1; Massanutten Mt., 1.
West Virginia. Hardy County, 1. Pendleton County: radius of 2 mi. Smoke Hole, 1[74]. Greenbriar County: White Sulphur, 2[60].
Wisconsin. Douglas County: Gordon, 1[102]. Vilas County: Mamie Lake, 4. Dunn County: Colfax, 4[102]; Meridean, 1[102]. Door County: state game farm, 17[102]; no locality more definite than county, 1[102]. Dodge County: Rolling Prairie, 1[50]; Beaver Dam, 52[50]. Dane County: Wingra Lake, 1[102]. Waukesha County: Pewaukee, 2[102]. Racine County: Waterford Township, 2[102]. Rock County: Milton, 1[102]; Bowers Lake, 1[102]. Walworth County: Lane's Mill, 8 mi. N Elkhorn, 7 (1[102], 6[54]); Delavan, 7.