Part 87

Color.--Usually, posterior fourth of each upper lip and sometimes few hairs in front of ear, white; sides and top of head and neck posteriorly to, or behind, shoulders, black; dark areas at angles of mouth confluent with color of upper parts; tip of tail, black; remainder of upper parts near (n) Bay of Ridgway and Reddish Black, tone 4, pl. 344 of Oberthür and Dauthenay; chin and lips, whitish; remainder of underparts Warm Buff or near (16´ c) Ochraceous-Buff; near (12) Salmon-Orange in juveniles and small young; color of underparts extending distally on posterior sides of forelegs to wrists, but not to soles, and on hind legs to or slightly below knees. Least width of color of underparts, in seven specimens, averaging 18 (extremes 11-28) per cent of greatest width of color of upper parts; black tip of tail, in five adults and subadults, averaging 45 (extremes 41-50) per cent of length of tail-vertebrae.

Skull and teeth.--Male (based on three adults from Boquete): See measurements and plates 25-30; weight, 5 (4.5-5.4) grams; basilar length, 45.2 (42.8-48.3); zygomatic breadth more or less than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth less than postpalatal length; postorbital breadth more than length of upper premolars and more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth not less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum approximately same (more or less than) length of tympanic bulla; least width of palate less than length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 4-1/2 to 5-1/2 upper incisors; height of tympanic bulla less than distance from its anterior margin to foramen ovale; length of tympanic bulla more or slightly less than (approximately equal to) length of lower molar and premolar tooth-row or length of rostrum; anterior margin of masseteric fossa directly below posterior fourth of m2.

Female (based on subadult, type specimen and one adult from Siola): See measurements; weight, 3.3 and 2.1 grams; basilar length, 41.3 and 39.3; zygomatic breadth more than distance between condylar foramen and M1 and more or less than (about equal to) that between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth more than combined length of upper premolars or than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate more than length of P4 (less in the adult); anterior margin of tympanic bulla as far posterior to foramen ovale as width of five upper incisors; height of tympanic bulla less than (about half) distance from its anterior margin to foramen ovale; length of tympanic bulla less than length of lower molar and premolar tooth-row or than rostrum.

The skull of the one adult female from Chiriquí is 58 per cent lighter than the average of the two adult males.

The skull of the male of M. f. panamensis as compared with that of M. f. meridana, is heavier and averages larger in nearly every measurement taken. Relative to basilar length, tooth-rows, orbitonasal length, interorbital breadth and zygomatic breadth averaging narrower. Mastoid breadth always narrower. Tympanic bullae longer, narrower, and usually slightly less protruded. P4 and m1 larger. Dorsal outline of skull, viewed laterally, more convex. Postorbital breadth actually and relatively greater. Postorbital processes, mastoid processes, and sagittal crest not so well developed. Differences between skulls of females, in so far as known, similar to those described between males.

As compared with M. f. costaricensis, M. f. panamensis has a lighter skull averaging smaller in every measurement taken except interorbital breadth, which is greater. Relative to basilar length, width of rostrum, interorbital breadth and depth of skull at plane of upper molars, less. Tympanic bullae shorter, narrower, less protruded. P4, M1, and m1 larger. Dorsal outline of skull, viewed laterally, more convex. Postorbital breadth relatively and actually greater. Postorbital processes, mastoid processes, sagittal crest and lambdoidal crest less developed. No skull of an adult female of M. f. costaricensis is available for comparison.

Remarks.--This subspecies had not been recognized by previous workers because specimens from Panamá were supposed to be Mustela affinis Gray up until 1916, when Allen (1916:100) restricted the type locality of M. affinis to Bogotá, Colombia. At that time Allen referred specimens from Panamá to Mustela affinis costaricensis, and Goldman (1920:161) followed Allen.

The specimens examined show much variation. Part of this is geographic variation. For instance the specimens from Boquete approach M. f. costaricensis in size more than do those from farther south. Too few adult females have been seen to ascertain the amount of secondary sexual variation. Bangs (1902:49) suggested that the sex of no. 10113 was wrongly recorded and that it was not really a male. If so, this would reduce the range of apparent variation in size of males from Boquete by half and bring it into accord with the amount normally existing in adult males from one locality. No. 10113 is adult but the skin shows no mammae which would prove it to be a female instead of a pigmy male. Although even smaller than 10113, the type specimen is so much larger than females of M. f. meridana that I have wondered if it is correctly sexed. However, the fact that it was sexed by E. A. Goldman, a collector of wide experience, lessens the possibility that a mistake was made.

The color of the underparts is more restricted in panamensis than in any other subspecies of the species. Excluding the specimen from Mt. Pirre, the least width of color of the underparts averages 16 (extremes 6-24) per cent of greatest width of the color of the upper parts. This feature, together with the black color, imparts an appearance to the Panamá weasel that is strikingly like that of a mink. M. f. panamensis is one of the two blackest weasels; M. f. aureoventris is the other. Each of these subspecies occurs in a region of heavy rainfall and there clearly is a positive correlation between high humidity and intensity of color. The black tip of the tail, as regards extent, here reaches the maximum attained among Central and South American weasels. The foot soles are less hairy than in any other member of the subgenus Mustela. The tympanic bullae are lower and less inflated than in any other subspecies of the species.

Adequate specimens from central and southern Panamá may reveal the existence of one or more additional subspecies since animals from each of the three localities now represented differ from those from the other two and some of these differences are correlated with geographic position. However, specimens from all three localities agree in several features. For example all of them have the dorsal outline of the skull highly convex, transversely, and, more especially, longitudinally. In this respect they are sharply differentiated from any other American weasel. Nevertheless, M. f. panamensis is clearly a link between the North and South American subspecies and panamensis intergrades with the adjacent subspecies. The large size of the skull and teeth and the slightly more ventrally projected tympanic bullae of no. 10112 from Boquete approach features seen in M. f. costaricensis. The smaller size of skull and teeth of no. 178970 from Mt. Pirre are points of resemblance to M. f. meridana.

The type specimen was selected from a region where M. f. panamensis is thought to have its distinctive characters well developed. The specimen is not adult and, therefore, does not show as many differential characters as does a nontypical adult from Boquete. Nevertheless, the majority of the above mentioned differential characters are shown by the type specimen and an adult from the same place would, it is judged, show all the differential characters better than would an adult from Boquete.

Of the 11 skulls examined, 6 show no signs of having had the frontal sinuses infested with parasites.

Specimens examined.--Total number, 19, listed by localities from north to south and unless otherwise indicated in the United States National Museum.

=Panamá=: Boquete, 10 (3, 1, 1, 3, 1); Río Gariche [é], 5300 ft., 1; Siola, 1; Chiriquí, 1; Río Indio, near Gatún, 1; Mt. Pirre, 3 (2); Calovébora, 1 (locality not found, possibly misspelling of Calovébora); no locality more definite than Panamá, 1.

=Mustela frenata meridana= Hollister

Long-tailed Weasel

Plates 25, 26, 27, 37, 38 and 39

Mustela meridana Hollister, Proc. Biol. Soc. Washington, 28:143, July 10, 1914.

Putorius affinis, Robinson and Lyon, Proc. U. S. Nat. Mus., 24:147, October, 1901; Allen, Bull. Amer. Mus. Nat. Hist., 30:256, December 2, 1911.

Mustela affinis, Osgood, Field Mus. Nat. Hist. Publ. 155, zoöl. ser. 10:61, January 10, 1912.

Putorius macrurus, Allen, Bull. Amer. Mus. Nat. Hist., 31:92, April 19, 1912.

Mustela affinis affinis, Allen, Bull. Amer. Mus. Nat. Hist., 35:100, April 28, 1916 (part).

Mustela affinis costaricensis, Allen, Bull. Amer. Mus. Nat. Hist., 35:101, April 28, 1916 (part).

Mustela frenata meridana, Hall, Carnegie Instit. Washington Publ. 473:110, November 20, 1936; Hall, Physis, 16:175, 1939.

Type.--Male, subadult, skull and skin; no. 123341, U. S. Nat. Mus., 1630 meters elevation, Montes de Mérida, near Mérida, Venezuela; August 14, 1903; obtained by S. Briceno.

The skull (plates 25 and 26) lacks the right exoccipital condyle and posterior half of the right zygomatic arch. The teeth all are present, unworn and entire. The skin is well made and complete.

Range.--Near sea level (San Julián) to 8500 feet (Montes de Culata, Mérida, Venezuela), and 9000 feet (Santa Elena, Colombia). Temperate to Subtropical life-zones of Venezuela and northern and western Colombia. See figure 29 on page 221.

Characters for ready recognition.--Differs from Mustela africana stolzmanni by absence of median, longitudinal, abdominal stripe of same color as upper parts, presence of p2 and two roots, rather than one root, on P2; from M. frenata panamensis in lighter color of upper parts (tone 3 rather than tone 4, pl. 344, Reddish Black, Oberthür and Dauthenay), flat rather than convex dorsal outline of skull immediately behind postorbital processes (see pl. 27); from M. f. affinis, in males, by lesser average breadth and length of skull and greater actual and relative size (see measurements) of facial part of skull; from M. f. aureoventris, in males, by lighter upper parts (tone 3 rather than tone 4, pl. 344, Reddish Black, Oberthür and Dauthenay) and by smaller skull and teeth (basilar length less than 45, length of m1 less than 6.3, width of M1 less than 4.8, outside length of P4 less than 5.7).