7<. XENODON. 



145 



Fig. 13. 



Skull of Xenodon merremii. 



Synopsis of the Species. 



I. Maxillary teeth 13 to 15 + 2 ; rostral shield not twice as broad 

 as deep. 



A. Ventrals not aiigulate laterally, 130-157 ; anal entire ; suh- 



caudals 35-50 ; scales iu 19 rows (rarely 21). 



Rostral once and a half to once and two 



thirds as broad as deep 1. cohohritiiis, p. 146. 



Rostral once and one third as broad as deep. 2. siispectus, 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. neuiviedii, p. 148, 



II. Maxillary teeth 6 to 12 + 2 ; rostral shield twice as broad 

 as deep ; anal usually divided. 



Scales in 21 rows ; 8 upper labials ; maxil- 

 lary teeth 10 to 12 + 2 5. severus, p. 149. 



Scales in 19 rows ; usually 7 upper labials ; 



maxillary teeth 6 or 7 + 2 6. merremii, p. 150. 



