478 REPOm' OF NATIONAL MUSEUM, 1898 



width of the brown rings, wliich are almost separated into two by an 

 imperfect bar beneath and a series of four round spots on each side 

 above, colored like the interspaces and involving four to six tubercles. 

 One of these rings above the shoulders crosses the forearm. Another 

 passes above the arms and across the middle of the thigh. The rest of 

 the legs, with the entire head and throat, are black, except at the top 

 of head behind the eyes, which is yellow. The tail, including the tip, 

 shows four black rings and three yellow ones. 



This regular arrangement of pattern on the body is appreciable only 

 in the young. With increasing age the rings become broken up, and 

 the pattern becomes an irregular, coarse reticulation of blackish, 

 embracing the yellow tubercles, one or more looking like differently 

 colored beads. The yellow predominates in some S])ecimeus, the black 

 in others. The head is always black, with its yellow parietal patch. 

 • Form clumsy and very heavy; head much broader than the neck, 

 much depressed and flat above, the sides vertical and approaching each 

 other anteriorly at an acute angle, but the muzzle broad and rounded. 



The animal is covered everywhere except below with large tubercles, 

 about the size of grains of No. 6 shot, each with a bony nucleus. 

 These are subhemispherical, but generally somewhat calyptrate, exhib- 

 iting a blunted apex which is directed a little backward. Most of these 

 exhibit a series of circular ridges and furrows parallel with the base of 

 the tubercle. These vary in number, never extend to the apex of the 

 tubercle, and are generally confined to the base. 



These tubercles are arranged in regular series, which run obliquely 

 backward from a shallow furrow along the back (irom behind the shoul- 

 ders to the tail) to the sides. They are, however, set in a frame of 

 much smaller tubercular scales, generally in single series, sometimes 

 more crowded. This framework constitutes a quite regularly hexag- 

 onal tessellation, with the rounded large tubercle set in the middle of 

 each piece. Besides the obliquely longitudinal arrangement of the 

 large tubercles, they may be traced in a more transverse one of fifteen 

 or sixteen on each side. 



On the belly and beneath the tail the tubercles change to quadrate 

 and nearly square tessellated ])lates, close together and without inter- 

 vening smaller ones. These also exhibit a tendency to arrangement in 

 reference to a median line. They are placed in transverse series, corre- 

 sponding in number Avith tliose of the sides and back, the change from 

 one to the other not being very strongly marked. There are about 

 twenty-five across the belly, and about sixty series from the end of the 

 throat to the groin, with five or six more in the pubic region, where the 

 plates are more irregular, the anal slit bordered by two median ones 

 larger than the rest. The tail shows about fifty-five whorls of tuber- 

 cles and plates corres))onding with those on the body. It is very thick 

 and blunt, subtetrahedral, and widening a little from the base to the 

 middle. 



