77. XENODON. 145 
Skull of Xenodon merremiz. 
Synopsis of the Species. 
I. Maxillary teeth 13 to 1542; rostral shield not twice as broad 
as deep. 
A. Ventrals not angulate laterally, 130-157 ; anal entire; sub- 
caudals 35-50 ; scales in 19 rows (rarely 21). 
Rostral once and a half to once and two ee 
thirds as broad as deep ............0. 1. colubrinus, p. 146. 4) 
Rostral once and one third as broad as deep. 2. suspectus, p. 147. 
B. Ventrals obtusely angulate laterally, 152-176 ; anal usually 
divided ; subcaudals 50-69, 
Scales in 19 rows; rostral as deep as broad. 3. guentheri, p. 147. 
Scales in 21 rows; rostral broader than deep. 4. newwiedii, p. 148, 
II. Maxillary teeth 6 to 1242; rostral shield twice as broad 
as deep ; anal usually divided. 
Scales in 21 rows; 8 upper labials; maxil- 
lary teeth Osteo Ie Oe ieee ess 5. severus, p. 149. 
Scales in 19 rows ; usually 7 upper labials ; . 
maxillary teeth Gor 7+2.. ......... 6. merremii, p, 150. 
VOL. Il. L 
