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Show 330 DR. n GADOW ON EVOLUTION [Mar. 20, counting these also the total sum would be 8 to 10 as stated by Boulenger, scarcely 10-12 as described by Gunther. Tibia with only 2 | rows of scutes. Femoral pores from 19-22. Coloration.-Throat whitish yellow, with a faint blue tinge across the middle. Collar black in the adult! Chest and belly black with many white specks on the sides of the body. The thighs, legs, and the whole tail are uniformly reddish yellow in the youngest forms and in the immature; in the adult the thighs are blue-black and chequered with white. The preanal region is blue; the tail beneath is speckled dusky. Upper parts (youngest forms): 3 pairs of thin stripes ; mid-field broad and buff. Immature : the 3rd pair of stripes is partly vanishing on the rump, so that field II. is merging into the buff of the mid-field. Adult: the first pair of stripes begins to be cut up by the encroaching black of field I. and by the black of the lateral field. The result is a light brown or buff ground-colour, with only one pair of pale stripes, and mottled with black on the sides of the body. The absence of light spots in the fields and in the vanishing stripes constitute a remarkable pattern in this large and completely isolated kind of lizard. CNEMIDOPHORUS GULARIS Baird. The collar is composed of several rows of large scales, and the posterior margin of the collar is formed entirely of large scales, without granules. The posterior side of the forearm is covered with one or more rows of large polygones or scutes, instead of granules; 6 pale stripes persist as unbroken lines. The dark fields are at first spotless, but soon a row of pale, mostly whitish spots appears in the first and second fields, without breaking up these fields (text-figs. 69 & 70). It is not easy to abstract a satisfactory, further definition from Cope's writings of what he understood by his C. gularis gularis. The femoral scales are said to be in 6-8 rows. The femoral pores are stated, in the key, to vary from 18-23, but in the text specimens with less than 16 are mentioned. The frenocular " occurs occasionally." The chest of the males is black, while the scales of the belly are margined with black; there are light spots on the flanks below the first stripe. Amongst an apparently large number of specimens from Chihuahua Cope mentions some, distinguished by him as C. g. gularis obsoletus, with wider and very obscure stripes, and with small obscure spots in the fields. Some of these specimens were the largest of the collection. In others, including " a good many small specimens," the stripes were wider, and the field-spots enlarged so as to be confluent occasionally with the light stripes. |