CROCt>DILIAN!S, LIZAKDS, AND SNAKES. 545 



Mciliuui; limbs loDger, hiiul limbs upjiressed, reachiug shoulder; tail lou;^', twice 

 body; oue row of supraoiulars; oue parietal, above light browu with t\yo rows 

 of very large pale-edged maroon spots A', picta Cope. 



Largest; limbs short, hind limb appressed, overlapping forefoot; tail equal body 

 plus head to front of eye; two rows of sui>raoculars; two parietals on each side; 

 above light brown with black, coarse vermiculations ...A', riveraiana Cope, 



Neither of tlie above speeies has been fouud thus far outside of the 

 limits of the State of California. 



XANTUSIA VIGILIS Baird. 



XaiilKnia riiiiHn Baird, Proc. Acad. Nat. Sci. Phila., 1.S5S, p. 255. — KouLEXciKU, 

 Cat. Liz. Brit. Mus., II 1885, p. 327. 



The hind leg extended twice forward reaches to the first gular fold, 

 and is contained about two and three-fourth times in head and body, 

 the head four and one-half times; the hind foot from heel nearly six 

 times. The claws are all very small; the digits covered beneath by a 

 series of transverse and imbricating plates. 



The color above generally is a dull brownish yellow varied with small 

 blackish spots on single tubercles. The young specimens exhibit a yel- 

 lowish vermiculation on a brown 

 ground distinctly seen on the 

 sides of body, neck, and head. 

 There are two yellowish X3aral- 

 lel lilies from tlie supraoculars 

 down the back of the neck be- 

 coming finally lost, and between 

 these on the back of the neck i'lg. 97. 



, 1 • /. 1 XANTUSIA VIGILIS Baiud. 



are two more, making four yel- 

 low lines on the nape. The cat. no. 19J, u.s.x.m. 

 under parts are whitish. 



In this species the head is short and covered above by a small num- 

 ber of very large plates. It is bounded behind by a constriction which 

 borders the posterior extremity of the large occipital plates, i)asses 

 through the ears, i)ast the end of the lower jaw and across the throat, 

 thus completely separating the neck from the head. The head is short, 

 broad, pyramidal, and quadrangular; the sides nearly vertical; the 

 rostrum rather pointed, its upper outline convex. There is a very large 

 hexagonal interparietal plate (the largest on the head), behind which 

 are two other irregularly pentagonal postparietals side by side, applied 

 against the two posterior faces. The oblique lateral borders are in 

 contact with an elongated pentagonal plate, and the anterior with two 

 adjacent subtriangular parietal plates, the long sides nearly equal. 

 These cover the whole supraorbital space, are in contact behind only 

 with the interparietal and parietal plates, excepting a very small one, 

 po-stero externally. The plate which represents the frontal is rhom- 

 boidal, broader than long, the lateral corners truncated and in contact 

 with the supraoculars. This, with the frontoparietals, completely 

 NAT MUS 1)8 35 



