222 ZOOLOGY. 



small, odd occipital, on each side of which, and immediately in advance of a large pair of post- 

 occipitals, is seen a pair of small plates. Two more pairs, equal in size to the last, may he 

 ohserved on either side of the large post-occipitals, and finally, hehind the latter a series or two 

 of quite small plates, limiting the occipital region. The nostrils open in one single plate ; 

 there are three lorals, one forming the continuation of the surciliary ridge, ahove which and the 

 nasal, hetween these and the frontals, there are four minute, elongated plates irregularly dis- 

 posed. The surciliary ridge is composed of six ohliquely superposed lamina3. The surocul- 

 aries are nearly as large as the prefrontals, and surrounded hy a series of small plates. The 

 suhorhital series consists of two plates only, a very long one heneath the orbit, and another 

 rather small anteriorly, their inner crest or ridge being well marked. The posterior rim of the 

 orbit is margined by small plates alike the temporal group. The surface of the lids is minutely 

 granular ; their margin is provided with a double series of very narrow, elongated, and very 

 small plates. The rostral is transversally elongated, but quite low, or else narrow. The upper 

 labials, five in number, are very narrow and elongated, increasing in length from the first to 

 the fourth inclusive ; the fifth is equal to the first. The supralabials are very exiguous ; the 

 middle ones being the longest. The symphyseal is larger than the rostral. The inferior labials, 

 four in number, gradually lose their width posteriorly ; the third is the longest ; the fourth is 

 the smallest of all. There are five pairs of mental shields, diminishing in size posteriorly; the 

 shields of the anterior pair being contiguous upon their inner margin. Between the inferior 

 labials and the mentals a trijsle series of elongated scutellfe or shields may be observed, one 

 series only extending to the posterior half of the anterior inferior labial and anterior mental 

 shield. The temporal shields are well developed, slightly imbricated, rounded jDOsteriorly, and 

 carinated. The neck exhibits but a slight loose elevation of the skin, and is protected by acute 

 and carinated scales, somewhat smaller than those of the back and sides. A small space imme- 

 diately behind the ear is granular, though not as minutely as about the axillas. 



The dorsal scales are large, subrhomboid, subacute posteriorly, and strongly carinated; they 

 are smaller upon the neck, and diminish gradually in size towards the sides of the body and 

 along the tail, where they constitute longitudinal series, instead of being arranged in verticiles 

 or else concentrically. Upon the origin of tail their posterior margin is rounded and subacute; 

 farther behind they gradually elongate, and the carina, instead of occupying the middle line of 

 the scale, becomes oblique. Along the inferior surface of that organ they are more uniform 

 and more slender. 



The limbs are very slender, and, when stretched alongside with the body, the anterior do not 

 reach the setting on of the thighs, and the posterior the ear opening, in which respects, as in 

 many others, this species may be distinguished from P. gracilis. The upper surface of these 

 organs, from their origin to the tip of the fingers, is covered with carinated scales, similar in 

 shape, though a little smaller than those of the sides of the back. They are plate-like on the 

 upper surface of the fingers, and obsoletely carinated. On the palm of the hands and sole of 

 the feet they are the smallest of all, except on the inferior surface of the arm and the anterior 

 tibio-metatarsal region, where they approximate the granular aspect of the posterior surface of 

 the thighs. 



The inferior surface of the head, neck, and abdomen, is covered with uniform scutellaj, some- 

 what smaller under the neck, and likewise diminishing in size towards the sides of the abdomen. 

 The average size of these scutellas is smaller than the dorsal scales. Their posterior margin is 

 rounded, and their surface slightly carinated from the chin to the preanal region, on the margin 

 of which there are very small plates. The postanal region is granulated like the posterior sur- 

 face of the thighs. 



The ground-color is uniform deep brown, with a reddish tint from the posterior third of the 

 body to half the length of the tail. The sides bear two parallel light vittre, the upjiermost 

 extending from the occiput to the base of the tail, the other from the auditive ajaerture to the 

 setting on of the hind legs. The inferior surface is unicolor, whitish or yellowish, with a me- 



