Western Frog

Rana pretiosa Baird and Girard

Colour.—Variable; dull or bright yellowish or reddish brown on head, back, and upper surfaces of arms and legs. Few or many irregular, roundish black spots--like splashes of ink--on the back between the lateral folds. Lower sides light yellowish grey, unspotted. Underparts light, obscurely or conspicuously marbled with greyish brown. Salmon-red on undersurfaces of legs, and in a more or less conspicuous U-shaped marking on the belly. A light glandular streak from under the eye to the arm, interrupted at the end of the jaw. Iris bright yellow, not orange-coloured or bronze.

Measurements.—Size medium, i. e. male 2 to 3 inches; female 3 to 4 inches in length. Leg to the heel as long as the body (i. e. forward to the ear). Foot conspicuously longer than lower leg.

Structure.—The skin is everywhere rough, even in the region of the ear. Lateral folds distinct. Head rounded, broader than long. Ear smaller than the eye. Head not conspicuously angled along the lines between eyes and nostrils. Nostrils round. Eye not large, set obliquely, so as to be but slightly elevated, and so as to face more dorsalwards than is usual. The foot has broad webs extending to the tips of all the toes, except the fourth, which has the short terminal joint free. The whole lower surface of the foot, as well as the buttocks and outer surfaces of legs (especially of lower leg), very rough with crowded tubercles. The inner tubercle of the foot is small, and there is a small tubercle opposite this on the sole.

Range.—Northwestern North America, as far east as the foot of the Rocky Mountains in Montana, north to Puget Sound, and south to southern California.

Colour.—Dull olive or greyish brown; sometimes brick-red. Upper surface may be obscurely spotted with dark. Upper jaw spotted irregularly. Iris metallic yellow. Legs and arms barred with dark. Underparts white, mottled anteriorly, and bright yellow posteriorly. Much yellow around the arm insertion. Webs yellow.

Measurements.—Size small, i. e. length 1 1/2 to 2 1/2 inches. Head short and broad. Legs very long; length to heel equals the total length of the frog, and sometimes exceeds it. Tibia longer than femur.

Structure.—Skin thick and coarse; unusually warty over all upper parts. Underparts smooth; buttocks granular. Lateral folds broad, not elevated, very inconspicuous. Muzzle projects beyond lower lip. Nostrils small. Ear round, smaller than eye, indistinct because covered with fine warts, as is the surrounding skin. The fold extending over the ear from eye to shoulder is indistinct. Canthus rostralis prominent. Space between the eyes greater than the width of the eyelid. Arms well developed; fingers long, with small tubercles under the joints. Foot with broad webs extending quite to the expanded tips of the toes. Inner sole tubercle medium in size; outer tubercle small.

Range.—Rana boylii Baird and Girard, is reported from California and Oregon. (Eldorado County, Ashland, Ore Shasta County; Mill Valley, Marin County, Cal.)

Colour.—Chocolate-brown or brownish olive, with four narrow lengthwise stripes of bright golden brown. There are two of these stripes on each side. One occupies the position usually held by the lateral fold (i. e. from the posterior part of the eye backward); the other lies below this, and extends along the middle of the side. The lower stripe is continuous with a stripe of bright golden brown extending from the shoulder forward along the jaw. Throat yellow, speckled with bronze. The sides of the frog have large dark spots on a metallic, brownish yellow back-ground. There are small black spots on the back and sides between the stripes. The belly and undersurfaces of the arms are yellowish white, spotted and mottled with rich brown. Under-surfaces of legs vividly striped lengthwise with yellow and brown; stripes continued on tibia and foot.

Measurements.—Size somewhat below medium, i.e. length 2 to 2 1/2 inches. Head long; length contained three times in total length. Space on top of head between eyes unusually narrow (half width of eyelid). Leg short length of leg to heel equals length of body forward to the ear. Tibia and femur equal. Foot relatively long; fourth toe much the longest; third longer than fifth.

Structure.—Skin relatively smooth and wet. Head pointed, upper jaw projecting over the lower. Canthus rostralis prominent. Eye peculiarly bulging extends beyond the jaw on the sides of the head, so that it can be seen from below. Ear larger than eye, and very distinct, surrounded by a circular ridge of skin. Inconspicuous fold of skin from eye over ear to shoulder. No lateral folds. A groove marks the middle of the back. Fingers slender; first thickened at base. Web broad and conspicuous; two joints of fourth toe free. Inner sole tubercle of medium size; outer lacking.