194 C0LTrBRIDJ5. 



a. Eye rather small ; frequently two prseoculars. rp_ gQl. 

 Scales in 17 or 19 rows ; ventrals 139-152. 1. leptocephalus. 

 Scales in 21 or 23 rows ; ventrals 152-172. 2. vagrans, p. 202. 



b. Eye moderate or large ; a single prseocular. 



a. Scales in 17 rows, all keeled . 3. ehrijsoeephalus, 



jS. Scales in 19 or 21 rows, the keel on the outer scale, if 

 present, weaker than on the others ; suboaudals not 

 more than 100. 



Frontal hardly once and a half as long 



as broad ; second row of scales feebly 



keeled 4. sealiger, p. 203. 



Frontal at least twice as long as broad . . ,5. scalaris, p. 204. 

 Frontal once and a half to once and three 



fourths as long as broad 6. ordinatus, p. 205. 



y. Scales in 19 rows, all with equally strong keels ; sub- 

 caudals 86-127 7. saurita, p. 212. 



c. Eye moderate ; two or three prseoculars. [p. 214. 



8. multimaculatiis, 



[p. 214. 

 2. Second row of scales smooth .... 9. rufopunctatus, 



B. Anal entire ; two superposed anterior temporals. 



10. pealii, p. 214. 



C. Anal divided. 



1. Scales in 15 or 17 rows ; usually a single anterior tem- 

 poral. 



a. 8 upper labials, usually three entering the eye ; scales 



keeled. 



Scales strongly keeled ; subcaudals more 



than 50 11. picturatus, p. 215. 



Scales feebly keeled, smooth on nape ; 2 



postoculars 12. truncatus, p. 216. 



Scales feebly keeled, smooth on nape ; 3 



postoculars 13. celehicus, p. 216. 



b. 8 upper labials, two entering the eye ; scales smooth. 



Scales in 17 rows 14. fuliginoides, p. 217. 



Scales in 15 rows 15. variegatus, p. 217. 



c. 6 upper labials, two entering the eye. 



Scales strongly keeled ; head narrow and 



elongate 16. swinhouis, p. 218. 



Scales very feebly keeled ; a groove along 



the middle of the nape . . '. 17. nuchalis, p. 218. 



