106 COLUBRID.S. 



obliquely, at least on the anterior portion of the body ; ventrals 

 rounded or angulate laterally. Tail long ; subcaudals in two rows. 

 Central and South America. 



Fig. 10. 



Maxillary and mandible of Leptophis liocercus. 



Synopsis of the Species. 



I. Loreal present (rarely absent). 



A. Scales smooth. 



Nasals not elongate ; loreal subquadrate . . 1. ceruginosus, p. 107. 

 Nasals elongate ; loreal thrice as long as [p. 107. 



deep 2. depressirostris, 



B. Scales keeled, except the outer row. 



Loreal once and a half as long as deep ; 



ventrals without trace of lateral keel . . 3. modestus, p. 107. 

 Loreal twice to thrice as long as deep ; 



ventrals feebly angulate laterally 4. mexicanus, p. 108. 



C. Five median rows of scales feebly keeled. 



5. cuprevs, p. 109. 



D. Only the scales of the series on each side of the vertebral 



keeled. 



Ventrals not angulate, 160 6. saturatus, p. 110. 



Ventrals feebly angulate laterally, 175-186 7. diplotropis, p. 110. 

 Ventrals feebly angulate laterally, 144. ... 8. bilineatus, p. 111. 



II. Loreal absent. 



A. Scales in 15 rows, keeled ; ventrals more or less distinctly 

 angulate laterally. 



Scales of vertebral row more feebly keeled 



than the one or two on each side of it ; 



frontal not more than once and a half as 



long as broad 9. occidentalis, p. 111. 



Scales more or less distinctly keeled, the 



keel on the middle row more feeble, or 



obsolete ; frontal at least once and a half [p. 112. 



as long as broad 10. nigromarginatus, 



