Part 53

Characters for ready recognition.--Differs from M. f. peninsulae in finer, softer pelage and shorter (less than 15.8 in ad. ) 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:

Length Length Catalogue Sex Locality Total of of hind no. length tail foot 47165 Box Springs, 454 160 48 Talbot Co., Georgia

47166 Box Springs, 435 147 47 Talbot Co., Georgia

47167 Box Springs, 422 145 45 Talbot Co., Georgia

41023 Thomas Co., 443 140 47 Georgia

41025 Grady Co., 395 142 47 Georgia

223880 Okefinokee Swamp, 416 145 49 Georgia

198 Okefinokee Swamp, 425 140 48 Georgia

Average 7 427 146 47

49385 Gainesville, 396 124 45* Alachua Co., Florida

41024 Thomas Co., 380 125 41 Georgia

51527 Talbot Co., 376 128 43 Georgia * [not typical]

The length of the hind foot averages less than the basal length in both males and females. The tail averages 52 per cent as long as the head and body in males and 51 per cent in females. Average differences in measurements of the two sexes are: Total length, 49; length of tail, 19; length of hind foot, 5. An adult male, no. 41023, and an adult female, no. 41024, each taken in February, 1929, on the Sinkola Plantation, Thomas County, Georgia, weighed 15 ounces (425 grams) and 7 ounces (198 grams) respectively according to Charles O. Handley.

Externals.--As described in Mustela frenata noveboracensis, except that hairiness of foot-soles slightly less than shown in figure 19.

Color.--Upper parts, in summer, near tone 4 of Burnt Umber of Oberthür and Dauthenay, pl. 304. In winter lighter, between tones 3 and 4 of Raw Umber of Oberthür and Dauthenay, pl. 301. Dark spot at each angle of mouth present or absent. Underparts ranging from Massicot Yellow to Cream Buff except on chin and upper lips which are white. Tip of tail black. Upper parts of uniform color. Color of underparts extends distally on posterior sides of forelegs over antipalmar faces of toes and on medial sides of hind limbs to ankles. Least width of color of underparts averaging, in a series of five males from Talbot Co., Georgia, 29 (extremes 24-34) per cent of greatest width of color of upper parts. Black tip of tail in same series, averaging 65 (extremes 60-70) mm. long, thus longer than hind foot and averaging 43 per cent of length of tail-vertebrae.

The spot at the angle of the mouth is absent in one-third of the specimens examined. The upper lips are white in specimens from the southern part of the range of olivacea but in the northern part of the range of the subspecies the upper lips are dark colored as in noveboracensis.

Skull and teeth.--Male (based on 5 adults from Talbot Co., Georgia): See measurements and plates 16-18; weight, 5.3 (5.0-6.4) grams; basilar length, 48.3 (45.8-50.1); zygomatic breadth more or less (usually less) than distance between condylar foramen and M1 and more or less (usually more) than distance between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth more or less than (averaging about equal to) postpalatal length; postorbital breadth less than length of upper premolars and more or less than (about equal to) width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth more or less than (about equal to) distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; least width of palate less than greatest length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 5 upper incisors; height of tympanic bulla not less than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer than rostrum (one exception); anterior margin of masseteric fossa below posterior half of m2.

Female (based on 2 adults from Thomas Co., Ga., and one from Talbot Co., Ga.): See measurements and plates 31-33; weight, 3.8 (3.5-4.0) grams; basilar length, 43.4 (42.7-44.0); zygomatic breadth less than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and more or less (usually more) than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate less than greatest length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla not less (usually more) than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer than rostrum.

The skull of the female averages 28 per cent lighter than that of the male.

Compared with the skull of M. f. peninsulae, of which only one good skull, and that a female, is available, that of M. f. olivacea averages smaller and has relatively and actually smaller and less inflated bullae. As compared with the skull of M. f. noveboracensis, that of olivacea in the case of males is larger in every part measured and relative to the basilar length is broader across the zygomatic arches and mastoids. However, the rostrum and interorbital region are relatively narrower. The orbitonasal length is relatively less. The tympanic bullae are broader and more inflated. The same differences hold as between females of noveboracensis and olivacea. Indeed, the females of these two races differ more than do the males. Additional, selected differential cranial characters in the females are, in olivacea, as follows: Weight averaging 3.8 grams rather than 1.7 grams; braincase with, rather than without, sagittal crest; anterior border of tympanic bulla separated from foramen ovale by breadth of less than, rather than breadth of more than, 4 upper incisors (including I3); height of tympanic bulla not less than, rather than less than, distance from its anterior margin to foramen ovale; squamosal bone, between anterior margin of tympanic bulla and foramen ovale, ventrally concave rather than ventrally convex. Comparisons of the skulls with those of M. f. arthuri and M. f. primulina are made in the accounts of those subspecies.

Remarks.--Excepting two young specimens from South Carolina in the Charleston Museum, no specimens of this race of large weasel seem to have been preserved until Arthur H. Howell, in the course of his study of the mammals of Alabama, procured specimens on which his name, olivacea, was based. Later, Francis Harper obtained three instructive specimens from Okefinokee Swamp. Really adequate material, for the localities represented, owes its preservation to the alertness of Charles O. Handley, when he resided at Thomasville, Georgia, and to Hallie E. Fuller of Geneva, Talbot Co., Georgia.

The distinctness of M. f. olivacea from M. f. peninsulae is not satisfactorily established due to inadequate material of peninsulae. Differences shown by the specimens seen indicate that, as compared with olivacea, peninsulae is larger, has transversely wider light-colored underparts which possess more yellow, and a larger skull with more inflated tympanic bullae. In each of these characters, olivacea is intermediate between noveboracensis on the north and peninsulae on the south. The question arises, therefore, whether the animals here recognized under the name olivacea really constitute a recognizable subspecies or instead are only representatives of a subspecies which reaches its extreme development in Florida. In the latter event, the name peninsulae would apply to all. Examination of more material from Florida, especially from the southern half of Florida, will be necessary to answer this question.

This large weasel of the southeastern United States is remarkably different from noveboracensis. Indeed, were it not for actual intergrades such as the two from Fort Payne, Alabama, and York, South Carolina, which are described in the account of M. f. noveboracensis, and the six specimens from northwestern Alabama, which are referred to olivacea, the systematist, I believe, would have little or no hesitancy in designating the two as distinct species, especially on the basis of differences to be seen in the skull.

Not only are the two forms structurally more different than usually is the case but between two geographically, adjacent subspecies of the same species of mammal, but the belt where intergradation occurs appears to be narrow. Nevertheless, when material of the two races is laid out in geographic order, and examined in mass, certain features are seen to undergo gradual change as a person's eye travels from specimens from, say, the center of the range of noveboracensis to specimens from southern localities adjoining the territory occupied by olivacea. One of these features subject to gradual change is the color of the underparts. Beginning at the Adirondacks of New York where a large number of the specimens have white underparts, the underparts become more intensely yellowish southward through the range of noveboracensis into that of olivacea. Indeed, this progressive trend seems to continue right on southward through the range of olivacea into that of peninsulae. Turning in the opposite direction we find that the least width of the underparts decreases gradually northward toward the range of noveboracensis. There is, likewise, a decrease to the northward in length of the skull and relative, as well as actual, narrowing of the braincase and tympanic bullae. However, in least width of color of underparts and the mentioned cranial features, the trend stops relatively abruptly at the southern boundary of the geographic range of noveboracensis and does not continue on, northward, into the range of noveboracensis as is the case with the change in intensity of yellowness of the underparts.

Two males, in the United States National Museum, Biological Surveys Collection, from near Leighton, Alabama, no. 178386 from the Tennessee River nine miles north [of Leighton?] and no. 180240 from La Grange Mountain, although clearly referable to olivacea on the basis of cranial characters, show some approach to noveboracensis in lesser size of the skull and agree with noveboracensis in the narrowness of the color of the underparts. Also, these specimens, like others from the northern part of the range of olivacea, for instance, no 31.227, Charleston Museum, from Mayesville, South Carolina, have the color of the underparts extended only part way out on the hind limb toward the foot. In specimens of olivacea from the southern part of its range the color of the underparts is extended onto the hind feet and this trend reaches its extreme in peninsulae, specimens of which have the feet and larger parts of the limbs marked with the light color of the underparts.

An adult female, no. 32.32, Charleston Museum, although typical of olivacea in most respects, is nevertheless an intergrade. The teeth are as small as in some specimens of noveboracensis. The size of the skull is only slightly nearer that of olivacea than it is to that of noveboracensis. The proportions of the skull, however, are distinctly those of olivacea.

Five other specimens, from northwestern Alabama, namely two from eight miles north of Nauvoo, two from Shoal Creek, and one from White Creek, also show intergradation between noveboracensis and olivacea. The remarks concerning color and color pattern of the specimens from Leighton apply equally well to the five from northwestern Alabama. In cranial characters, no. 51658 from Shoal Creek is referable to olivacea, as also is no. 51677 from the same place, providing it is a female rather than a male as sexed by the collector. No. 57146 from White Creek also is referable to olivacea although the skull shows some approach to that of noveboracensis. Of the two males from near Nauvoo, no. 51652 is to me indistinguishable from noveboracensis, but no. 51653 does have some characters of olivacea, although on the whole, the latter, too, seems to be a little nearer noveboracensis than olivacea. However, because the mean of these seven specimens from northwestern Alabama is nearer olivacea than noveboracensis the former name may be applied.