56 PHRYNOSOMACORNUTA. 



the same size; the occipital plate is small and subround; the remaining parts of the 

 occipital space is covered with small scales and small conical pointed tubercles, 

 sometimes grooved. The rostral plate is small, pentagonal, and rounded above. 

 The nasal plates are single on each side, circular, narrow, surrounded by five or 

 six small polygonal scales, with the opening for the nares nearly in the middle. 

 The nostrils are very near the snout, latero-superior, and open almost vertically 

 within the internal margin of the superciliary ridge. The eyes are small and 

 sunken, with the pupil black and the iris dark grey. The margin of the upper jaw 

 is covered with about twelve small quadrilateral labial plates, all nearly of the same 

 size; the three or four posterior being rather smaller. The upper margin of the 

 lower jaw is covered with about as many labial plates, and of nearly the same size 

 and form; its inferior margin presents a series of six horny points on each side, placed 

 horizontally, and increasing in size from the anterior to the posterior, and give a 

 serrated appearance to the inferior and lateral margin of the lower jaw. Above 

 these points, but below the labial range of plates, are two series of small scales. 

 At the posterior border of the occiput is a transverse row of prominent spines, nine 

 in number, extending from near the front of one external meatus of the ear to the 

 other; two of these spines are very long, and occupy the posterior border of the 

 occipital region; three are placed externally to these on each side, and decrease 

 gradually in size from above downwards; the ninth spine, which is smallest of all, 

 is situated between the two central or longest: these spines are nearly conical, but 

 are flattened at their bases. The external meatus of the ear is large and oval, most 

 extensive in the vertical direction; this opening is granulated posteriorly, and is a 

 little prominent in front, where there are three or four tubercles, with projecting 

 points. The neck is very short, which gives the head the appearance of being 

 attached to the shoulders, like the toad. The chin is covered below with small 

 rhomboidal scales; besides these are two rows of larger and pointed scales running 

 to the neck, within and parallel to the rows of spines that margin the lower jaw, 

 but separated from them by three or four series of small scales. The skin of the 

 neck is slightly folded transversely, but on the sides are larger folds that cover 

 depressions; the most remarkable is placed in front of the shoulder. The borders 

 of these folds are frequently armed with short spines. 



