428 
might be retained, I was induced to re-examine all the other African 
Coronellide. But I could not convince myself that such a genus 
would form a naturally defined group. Coronella cucullata, with 
its posterior maxillary tooth grooved ; Adlabes rufulus, with all the 
teeth equal in length; Coronella olivacea, C. fuliginoides, and pro- 
bably C. semiornata, with the posterior tooth longest; and finally, 
the three species of Meizodon, with the teeth gradually increasing 
in strength,—are so similar to each other in the proportions of the 
single parts, in the arrangement of the shields of the head, in their 
physiognomy, in the structure and number of the scales, in the dark- 
ness of the colours, that the other character, that of dentition, must 
give way for generic distinction—the more so as it is very difficult 
in many specimens, even in some species *, to say which of the dif- 
ferent categories of dentition is prevalent. 
I add, for completeness’ sake, the diagnosis of Metzodon regularis : 
CoroNELLA (MEIzODON) REGULARIS. 
Syn. Meizodon regularis, Fischer, Hamb. Abhandl. Gebiet Na- 
turwiss. 1856, p. 112; Gthr. Catal. Col. Snakes, pp. 109, 250. 
Scales smooth, in nineteen rows ; anal bifid; two posterior oculars. 
Eight upper labial shields, the fourth and fifth coming into the 
orbit. Entirely blackish-olive ; each scale with a black centre aud 
a pearl-coloured speck at the upper edge ; posterior part of the neck 
with a broad, darker, lighter-edged collar. 
Hab. West Africa. 
The typical specimen is in the Hamburg Museum ; another in the 
Collection of the British Museum. 
Coronetia (MErzopon) BiToRQUATA, n. sp. 
Scales smooth, in nineteen rows ; anal bifid ; two posterior oculars, 
Eight upper labial shields, the fourth and fifth coming into the orbit. 
Brownish-olive above; a black band across the occipitals, a second 
across the neck, and a black spot behind the latter on each side of 
* In many specimens of Adlabes rufulus the teeth are, strictly speaking, not 
equal, but increase in strength posteriorly, In Liophis<cobella the character of 
the longer posterior tooth is little marked ; and there are specimens in which all 
the teeth are of equal size. 
