272 



COLXTBEIDjE. 



Prontal shorter than its distance from 



the rostral ; 48-50 scales round the 



body . . 6. ccerulescens, p. 275. 



Frontal as long as its distance from 



the end of the snout ; 42 scales 



round the body 7. frontalis, p. 276. 



2. 25-29 scales round the neck, 35-39 round the body. 



a. Scales all imbricate ; posterior chin-shields separated by 



Rostral as deep as broad 8. Jcingii, p. 276. 



Eostral broader than deep 9. nigrocinctus, p. 277. 



b. Scales on the body juxtaposed ; posterior chin-shields in 

 contact with each other. . 10. mamillaris, p. 277. 



B. A single anterior temporal, 



1. 27-31 scales round the neck, 40-48 round the body ; 



ventrals 345-500. 



Rostral broader than deep ; frontal a 



little longer than broad ; scales 



imbricate; seven upper labials . . . . 11. elegans, p. 278. 

 Rostral deeper than broad ; frontal 



longer than broad ; scales on body 



juxtaposed 16. cantoris, p. 281. 



Rostral nearly as deep as broad; 



frontal much longer than broad . . 17. fasoiatv,s, p. 281. 

 Rostral a little broader than deep ; 



frontal slightly longer than broad; 



scales imbricate ; six upper labials. 18. brookii, p. 282. 



2. 19-23 scales round the neck, 29-33 round the body 



ventrals 225-337. 



a. Seven or eight upper labials ; rostral as deep as broad ; 

 frontal twice as long as broad. 



12. padficus, p. 278. 

 5. Six upper labials. 



Rostral broader than deep ; posterior 



chin-shields separated by scales . . 13. latifasciatus, p. 279. 

 Eostral broader than deep ; posterior 



chin-shields in contact with each 



other 14. coronatus, p. 279. 



Rostral as deep as broad; posterior 



chin-shields in contact with each 



other 15. gracilis, p. 280. 



3. 25 scales round the neck, 35 round the body ; ventrals 329. 



19. melanoeephalus, p. 283. 



4. 33-40 scales round the neck, 40-50 round the body. 



Prontal shorter than its distance from 



the rostral ; ventrals 240-285 .... 20. torquatus, p. 283. 



