40 
row, having a triangular scutella at its anterior extremity, and 
two rows of scutellae on each side. 
The body was covered with hexagonal flat scales, those on 
the back narrowest; the throat with three or four rows of small 
scales; the belly with a hundred and eighty plates ; the tail with 
ninety three pairs of scutellae. Over the vent was one pair of 
scutellae ; at its sides four pair, the scales opposite to which were 
smaller than those on any other part of the body. 
The colour of the head and of the upper part of the body and 
tail was an uniform deep brown; that of the belly and under 
part of the tail a bluish lead colour, lightest in the middle. 
The whole of the under jaw and throat were white, which colour 
extended in a clouded streak some way down under the neck, a d 
fore part of the belly. 
In the general disposition of its colours, in the number, form, 
and arrangement of the scuta and scutellae, this animal approach¬ 
es most nearly to the Coluber Constrictor; from which however 
it is strikingly distinguished by its undulating back, by its body 
being larger in proportion to its length, and diminishing more 
suddenly at the vent, the tail shorter, the teeth much larger and 
more distant, and the colour brown instead of black 
This animal is probably amphibious, although it has not the 
flat tail of the Pelamides ; nor did the examination of its exterior, 
enable us to discover any thing in its structure, peculiarly adapt¬ 
ing it to a residence in the water, excepting only the remarkable 
facility of bending in a vertical direction. This motion, which 
may be observed in the leech, and various other aquatic animals, 
is quite as important as a horizontal one to an inhabitant of the 
ocean, and comparatively useless in an animal confined to the 
land. 
Internal Structure. 
The structure of the spine in this animal is very singular, and 
different from that of any serpent which we have seen, or known 
to be described. Its course throughout the greater part of the 
body is regularly undulating or flexuous, consisting of successive 
curves upward and downward. The structure of the different 
