194 APPENDIX F. REPTILES. 



Desc. — Vertical plate very broad, subhexagonal. Occipitals short. 

 Rostral very broad, high, more so than in the other species, outline 

 rounded. The interval between the opposite frontals, the rostral, and the 

 vertical occupied by a number of small plates, from 10 to 12, or more, 

 arranged without any symmetry, on each side and behind the small 

 azygos. _ The base of the rostral between the opposite prenasals is gen- 

 erally margined by these small plates, which sometimes, too, are seen 

 between the vertical and the anterior portion of the superciliaries. This 

 crowding of plates causes the anterior part of the forehead to be broader 

 than in H. simus. Eye small, its centre rather posterior to the middle 

 of the imaginary line connecting the tip of rostral with the lower angle 

 of the postlabial, which line scarcely crosses the eyeball. Orbital plates, 

 10-13 in number. Loral triangular, rather longer than high, separated 

 from the frontal by a small plate. Nasals rather short, occasionally with 

 the lower part of the nostril bounded by a small plate. Labials 8 or 9 

 above, all of them higher than long ; indeed, their vertical extension is 

 much greater than in any other species : the 6th highest ; centre of eye 

 over the junction of the 5th and 6th. 



Dorsal rows of scales 23, outer row smooth, rest all distinctly cari- 

 nated, the keels extending to the ends of the scales; those just behind 

 the occipital plates truncated, with obsolete carinse. Scales on the hind 

 part of the body rather broader and shorter than anteriorly ; the ine-. 

 quality scarcely evident in large specimens. 



Ground-color light brown or yellowish gray, with about 50 dorsal 

 blotches from head to tip of tail; the 39th opposite the anus. These 

 blotches are quite small, rather longer transversely, subquadrate, or 

 rounded, indistinctly margined with black, (obsoletely on the outside ;) 

 they cover 7 to 9 scales across, are 2 to 2-J long, and separated by in- 

 terspaces of l-§- scales, which are pretty constant throughout, though 

 rather narrower on the tail. On each side of the dorsal row may be 

 made out, under favorable circumstances, four alternating rows of 

 blotches ; the first on the contiguous edges of the scales of the first and 

 second exterior dorsal rows ; the second on the scales of the 3d row, and 

 the adjacent edges of those in the 2d and 4th ; the third on the scales 

 of the 4th, 5th, and 6th, and the adjacent edges of the 3d and 7th ; and 

 the fourth on the scales of the 6th, 7th, and 8th rows, and the adjacent 

 edges of those of the 6th. This last is opposite the intervals of the 

 dorsal series ; the rest alternate with it. The central inferior surface of 

 the abdominal scutellse is black, sharply variegated with quadrate spots 

 of yellowish white ; the portion of the scutellse entering into the side of 

 the body is yellowish white, with that part opposite the dorsal intervals 



