152 
ON THE PHYSIOONOMY OF SEEPENTS. 
lanceolate, carinated scales ; the tail flattened below ; belly 
convex. S. 140 + 196 Above of an olive-brown, marked 
by numerous dark-coloured, narrow, transverse bands in- 
closing light-coloured spots. From Cayenne. 
17. Herpetodryas Dipsas. Resembles the genus I)ip- 
sas in the form of its large head ; eyes very large ; scales 
smooth, large, and disposed in 13 rows: form thin, but 
vigorous ; tail very slender ; colour shining bluish-black. 
The lower and anterior parts are of a brovv nish-yellow, the 
last covered with marblings ; triangular spots on the sides. 
S. 194+ 130, A species of large size; a native of Ce- 
lebes. 
18. Herpetodryas Getulus. Its clumsy form approxi- 
mates it to the genus Coluber. Trunk thick ; abdomen 
angular ; head almost in the same line as the neck ; muzzle 
truncated, rostral plate arched ; eyes small. 21 rows of 
smooth lozenge-shaped scales ; S. 210 + 44.t Black varie- 
gated by bands and rays of a yellow colour interlaced with 
each other. From North America. 
19. Herpetodryas Cursor. Of a small size ; form of a 
Coluber ; lower part of the tail very convex ; 16 to 17 
rows of scales ; blackish, with 4 yellow rays above. PL 
195-hl05. F rom both Americas . 
psammophis 
Is the seventh and last genus of the Terrestrial Snakes. 
It comprehends those snakes which approach tree- snakes 
by their form, and by several points in their organization. 
The greatest number inhabit uncultivated plains, or sandy 
regions covered with bushes. They present an anomaly in 
the system of dentition, inasmuch as the posterior teeth 
and those in the middle are usually longer than the rest, 
and sometimes grooved. Their head is elongated, rather 
broad, and covered by plates, of which the vertical is very 
narrow ; the frenal region is in the form of a gutter. Some 
have a slender shape and a small body ; others, by their 
compact form, approach the genus Coluber. They inhabit 
^ [It probably should be 106 . — Tr.] 
t [This also seems an error. — T.i.] 
