162 IGXJANID^. 



h. Outer parietcils at least twice as 



large as inner 7. cannatus, p. 165. 



2. Ventral scales keeled 8. henninieri, p. 166. 



B. Parietal plates transversely divided. 



Upper head-scales smooth or feebly stri- 

 ated ; a dorso-lateral crest ; ventral 

 scales strongly keeled 1), aculeatas, p. 167. 



Upper head- scales smooth ; ventrals smooth 



or feebly keeled 10. iridescens, p. 167. 



Upper head-scales unicarinate ; ventrals 



keeled 11. enjthrogaster, p. 168. 



II. Head-scales small, parietals indistinct. 



A. No supraciliary crest. 



1. Upper head-scales not keeled ; a 



series of transverselj* enlarged 



supraoculars 12. formosus, p. 168. 



2. Upper head-scales keeled. 



43 scales round the middle of the body ; 



gular scales as large as dorsals 13. ornatus, p. 168. 



47 scales round the middle of the body ; [p. 1 69. 



gular scales smaller thau dorsals .... 14. tracliycephalus, 

 61 to 75 scales round the middle of the 



body 15. gueniheri, p. 169. 



B. A supraciliary crest. 



Posterior supraciliary scales compressed ; 



temporal scales imbricate 16. tricristatus, p. 170. 



Supraciliary crest ending in a large py- 

 ramid-shaped tubercle ; temporal scales 

 tubercular 17. dumerilii, p. 170. 



1. Lioceplialus schreibersii. 



Pristinotus schreibersii, Gi-avenh. N. Acta Ac. Leop.-Carol. xviii. 



1838, ii. p. 739, pi. hv. figs. 15, 16. 

 Steironotus schreibersii, Fitzing. Si/st. Rept. p. 70. 

 Liocephalus schreibersii, C'o/je, Proc. Ac. Philad. 1868, p. 123. 



Upper head-scales large, striated ; nasal in contact with the 

 rostral ; supraorbitals in contact ; supraoculars seven or eight, 

 band-like, separated from the supraorbitals by a scries of small 

 scales ; parietals two pairs on one row, subequal, or outer pair a 

 little larger. Sides of neck strongly plicate, covered with very 

 small granular scales. Dorsal crest low. Dorsal scales small, not 

 mucronate, the keels forming nearly straight longitudinal lines ; 



