SPECIES OF THE GENUS XANTUSIA. 53I 



pierced in a small scute at the junction of the rostral, in- 

 ternasal, postnasal, and first labial plates. The rostral is 

 broad and rather low, bounded by the first labial, nasal 

 and internasal plates. The two internasals are followed 

 by a large subquadrate frontonasal, which is sometimes 

 divided longitudinally, behind this are two prefrontals, 

 bordered posteriorly by the broad frontal and the first 

 superciliary plates. Each of the two frontoparietal plates 

 is in contact with the frontal, second third and fourth 

 superciliaries, first supratemporal, parietal, interparietal 

 and its fellow of the opposite side. The parietals and 

 interparietal are bordered behind by the two large occipi- 

 tals. One or more interoccipitals are sometimes present. 

 There is a row of small supratemporals along the outer 

 edge of the occipital and parietal plates. The two large 

 loreals are in contact below with the superior labials, and 

 above with the frontonasal and prefontal plates. The eye 

 is surrounded by a series of small plates, the upper five 

 of which are the superciliaries. Between this ring and 

 the larger loreal are two small plates. There are five su- 

 perior and three inferior labials to a point below the pupil. 

 The eye is large, without lids, and with vertical pupil. Its 

 diameter is contained about twice in the distance from 

 the end of the snout to the orbit. The ear opening has 

 a very weak anterior denticulation. The symphysial 

 plate is very long. The inferior labials are in contact 

 with the large sublabials. The first pair of the latter are 

 in contact on the median line. The back, sides, upper 

 and posterior surfaces of the limbs, and the gular regions, 

 are covered with subhexagonal granular scales. There 

 is a series of large quadrate plates along the edge of the 

 last gular fold. The quadrate ventrals are in fourteen 

 longitudinal and thirty-three or thirty-four transverse rows. 

 The preanal plates are arranged in three or four rows. 



