82 OPHIBOLUS. 



Genus OPMIBOl-US, Baird & Girard. 



Gen. Char. Body rather thick, tail short. Dorsal rows 21, (iu 

 one group 23,) the scales hexagonal, arranged in longitudinal series, 

 broad, short, scarcely overlapping, nearly as high as long, all per- 

 fectly smooth and lustrous. Abdominal scutellas 180-220 ; posterior 

 entire Subcaudal all bifid. Head short, depressed, but little wider 

 than the body. Eyes very small. Vertical plate very broad. Post- 

 orbitals two, the lower in notch between the 4th and 5th labials. 

 One anteorbital, like the loral, small. Nasals two, with the nostril 

 between them. Upper labials 7. 



Ground-color black, brown, or red, crossed by lighter intervals 

 generally bordered by black. 



The type of the genus is to be found in 0. Sayi, to which we would 

 refer for more full generic characters. The red species belong to the 

 genus Erythrolamjpr-us of Boie, as understood by Dumeril & Bibron. 



B. Dorsal rows 23. 



1. OpllibolUS Boylii, B. & G. — Black, with upwards of 30 broad 

 ivory white transverse bands widening on the sides. Dorsal rows of scales 

 23. 



Vertical plate distinctly pentagonal, longer than broad : more 

 elongated than in 0. Sayi. Sides nearly parallel, a little shorter 

 than the occipital plates. The sides of the head as in 0. Sayi. Dorsal 

 rows 23, the scales rather more elongated than in 0. Sayi. Outer 

 row a little larger, all the rest nearly equal. Back and sides black, 

 crossed by about 37 ivory-white bands, the 30th opposite the anus. 

 On the vertebral region these bands are about one and a half scales 

 wide, with the margins parallel to about the 7th outer row of scales, 

 where they begin to widefl, so as to embrace from five to seven scales 

 on the outer row. They continue of this width to the middle of the 

 abdomen, where they are either confluent with the white of the oppo- 

 site side, or are opposite to the black interval on the other side. 

 The black interval between the cross bands is some eight to ten scales 



