Part 90

Characters for ready recognition.--Differs from Mustela africana stolzmanni by absence of median, longitudinal, abdominal stripe of same color as upper parts, by presence of p2 and by two rather than one root on P2; from Mustela frenata macrura by Reddish Black, tone 4, plate 344 rather than Chocolate, tone 3, pl. 343 (of Oberthür and Dauthenay), or slightly darker color of upper parts; from M. f. affinis and M. f. meridana by darker color (tone 4 rather than tone 2, Reddish Black of Ober. and Dauth.) of upper parts and larger size of teeth (M1 with length more than 2.4 and breadth more than 4.7; P4 with outside length more than 5.9; length of m1 more than 6.2).

Description.--Unless otherwise stated, information concerning this subspecies is derived from the one referred specimen available, a young male, no. 34677, Amer. Mus. Nat. Hist.

Size.--Male: Total length, 470; length of tail, 160; length of hind foot, 50. Tail 51 per cent as long as head and body.

Female: Not known.

Externals.--Longest facial vibrissae black and reaching beyond ear. Carpal vibrissae reaching to or beyond apical pad of fifth digit; hairiness of foot soles slightly less than shown in figure 20.

Color.--Sides and top of head and neck posteriorly to shoulders black; white facial markings represented by only five white hairs anterior to right ear, one anterior to left ear and three far back on forehead; dark areas at angles of mouth confluent with color of upper parts; tip of tail black; remainder of upper parts near (n) Bay or Reddish Black, tone 4 of Oberthür and Dauthenay, pl. 344; chin whitish; remainder of underparts Warm Buff, deep orange in juvenile, type specimen, according to Gray (1864, pl. 8); color of underparts extending distally on posterior sides of forelegs to wrists but not reaching foot soles and on hind legs to or slightly below knees. Least width of color of underparts equal to 15 per cent of greatest width of color of upper parts. Black tip of tail equal to 27 per cent of length of tail-vertebrae.

In color, no. 34677 is, to me as it was to Allen (1916:101), indistinguishable from the darkest specimens (nos. 178970 and 10112) of M. f. panamensis. Therefore, M. f. aureoventris is one of the two darkest subspecies of weasels.

Skull and teeth.--Male: See measurements and plates 27-29; weight, 4.3 grams; basilar length, 45.8; zygomatic breadth approximately equal to distance between condylar foramen and M1 and to distance 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 greater than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth greater than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less (at least in young specimen) than length of tympanic bulla; least width of palate seldom if ever greater than length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of three (including I3) upper incisors; height of tympanic bulla not greater than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and shorter than orbitonasal length; anterior margin of masseteric fossa below anterior half of m2.

Skulls of males of M. f. aureoventris, and Mustela frenata macrura from the vicinity of Quito so closely resemble one another as not to be distinguished with the material now available, although the teeth of aureoventris are larger. Comparisons of the skulls of males with those of M. f. meridana and affinis, which are readily distinguishable from those of aureoventris, have been made in the accounts of those subspecies.

Female: Skull of adult unknown.

Remarks.--This subspecies of the Tropical Life-zone, or at least the Subtropical Life-zone, of Ecuador, in certain cranial characters resembles Mustela frenata macrura of the Temperate Life-zone. The two differ markedly in color. Nevertheless, a large number of the specimens collected in Ecuador are intermediate in color as well as in zonal distribution.

The type specimen is young or a juvenile. The measurements of no. 34677 from Gualea indicate an animal similar in size to M. f. affinis. Gray (1864:55) states that the type specimen measures "Length of body and head 6 inches, of tail 4-1/2 inches." The plate (pl. 8) accompanying Gray's original description (loc. cit.) is marked one-half natural size and represents the animal as having a head and body length of eight and one-half inches. One year later Gray (1865:115) gives the measurements of this species as "Length of body and head 12, tail 8 inches." Since he had at this time another specimen, larger than the type specimen (which specimen later, probably, became the type of Mustela affinis Gray), the larger measurements probably were taken from it.

Geographically, and as regards cranial characters, Mustela frenata aureoventris is most closely related to M. f. affinis and to the northern section of M. f. macrura, but in color to M. f. panamensis. M. f. aureoventris and M. f. panamensis are the two darkest-colored subspecies and each occurs in a region of extremely heavy rainfall. There is a skin only, no. 32620, Amer. Mus. Nat. Hist., from Munchique, obtained on June 1, 1911, which is appreciably darker than specimens of M. f. affinis in corresponding pelage and is intermediate between M. f. affinis and M. f. aureoventris in color as it is geographically. The specimen measures 495, 202, 52.

The name Mustela aureoventris Gray has been regarded by most authors as preoccupied by Mustela auriventer Hodgson (1841:909). However, the writer is not of this opinion and agrees with Thomas (1920:224) that "The name aureoventris is not invalidated by the auriventer of Hodgson, as, apart from 'one-letterist' differences, its first half comes from the adjective aureus, while Hodgson's name is based on the substantive aurum, so that not only the spellings but the derivations are different." The spelling of Gray's name should be aureoventris for this is the spelling in the original description which in pagination precedes the colored plate of the animal that is labeled Mustela aureoventris. Putorius brasiliensis var. aequatorialis Coues (1877:142) is the only name known to the writer that has been proposed as a substitute for Mustela aureoventris Gray.

Thomas (1920:224) treats Mustela macrura Taczanowski as a synonym of Mustela aureoventris Gray. Allen (1916:101) also treats the two names as applying to the same kind of weasel but regards aureoventris as preoccupied and therefore uses the name macrura. Taczanowski's original description (1874:311) and plate of Mustela macrura indicate an animal that is lighter colored than M. f. affinis. Gray's original description (1864:55) and plate of aureoventris indicate an animal that is darker colored than M. f. affinis. Indeed Gray (1865:115) in speaking of the type of aureoventris as compared with an adult from New Granada [= Colombia] that probably later became the type specimen of Mustela affinis, states: "The young from Quito is much darker than the adult;. . . ." Comparison of the plates accompanying the original descriptions of aureoventris and macrura well illustrate the difference stated in the written descriptions. My examination of the type specimens of M. macrura and M. f. aureoventris shows them to have been fairly accurately portrayed in the plates accompanying the original descriptions. Accordingly the two names are used for the two kinds of animals which appear, however, to be only subspecifically distinct.

Comparison of Gray's plate (1864, pl. 8) with the available specimens from South America indicates that the name aureoventris is based on an individual that is lighter colored than no. 34677 Amer. Mus. Nat. Hist., from Gualea, Ecuador, but on one which resembles no. 34677 more than it does the lighter-colored specimens from the Temperate Zone of Ecuador and northern Perú. Because Quito, Ecuador, is in the Temperate Life-zone and because the available specimens from this zone in Ecuador and northern Perú are distinctly lighter colored than Gray's plate representing the type of aureoventris shows this specimen to be, it is judged to have come from an altitude lower than that of Quito (9350 feet, according to Chapman, 1926:717); probably it came from the Subtropical Life-zone of Ecuador. Indeed Gray (1864:55) did not say that the specimen was collected or obtained at Quito but that it was ". . . received from Quito. . . ." Chapman (1926:717) has pointed out that Quito, since 1846 has been the distributing point for bird skins which specimens ". . . come from the vicinity of the city, from the 'Napo' region on the Amazonian slopes of the Andes, and from Nanegal, Gualea, and other localities on the Pacific side rarely below the Subtropical Zone." It is also pointed out that only some of the specimens are labeled with their approximate place of capture and that even then these localities cannot be accepted as definite; they indicate mainly whether the specimen is from the eastern or western side of the Andes.

The above mentioned considerations and information gained by study of the specimens cause me to think that the type is an intergrade tending toward the lighter-colored Mustela f. macrura of the Temperate Zone although sufficiently dark to be referred to the dark subspecies represented by no. 34677 Amer. Mus. Nat. Hist., from Gualea, Ecuador.

The skull of no. 34677 shows no infestation of the frontal sinuses by parasites.

Specimens examined.--Total number, 3, as follows:

=Ecuador=: Gualea, 1, Amer. Mus. Nat. Hist.

=Colombia=: 8325 ft., Munchique, 1, Amer. Mus. Nat. Hist. In the British Museum of Natural History, the type, (1).

=Mustela frenata helleri= Hall

Long-tailed Weasel

Plates 27, 28 and 29

Mustela frenata helleri Hall, Proc. Biol. Soc. Washington, 48:143, August 22, 1935; Hall, Carnegie Instit. Washington Publ. 473:110, November 20, 1936; Hall, Physis, 16:175, 1939.

Type.--Male, adult, skull and skin; no. 24133, Field Mus. Nat. Hist.; 3000 feet, Hacienda San Antonio, Río Chinchao, Perú; August 22, 1922. Obtained by Edmund Heller. Original no. 6589.

The skull (plates 27-29) is complete and unbroken. The teeth all are present, entire and but slightly worn. The skin is well made, unfaded, and in good condition.

Range.--Three thousand feet (type locality) to 6700 feet (Ambo), Tropical and Subtropical life-zones of eastern Perú. See figure 29 on page 221.