B O A. 
236 
This genus of serpents is remarkable for 
the vast and almost unlimited size of some of 
the principal species, which in India, Africa, 
and South America, are occasionally found 
of not less than twenty, thirty, and even thirty- 
live feet in length, and of a strength so pro- 
digious as to be able to destroy cattle, deer, 
&c. by twisting round them in such a man- 
ner as to crush them to deatii by continued 
pressure, after which they swallow them in a 
very gradual manner ; and when thus gorged 
with their prey, become almost torpid w ith 
repletion, and if discovered in this state, may 
without much difficulty be destroyed by 
shooting or other methods. There is reason 
4o suppose that these gigantic serpents are 
become less common now than some cen- 
turies backwards. 
There are nineteen species, viz. 
1. Boa constrictor. Of all the larger boa? 
this is most conspicuous, and is at once pre- 
eminent from superior ity of size and beauty of 
dolour : in this respect indeed it appears to be 
subject to considerable variation from age, 
«ex, and climate, but may be distinguished 
in every state from the rest of its tribe by the 
peculiar disposition of its variegations. The 
ground-colour of the whole animal, in the 
younger specimens, is a yellowish grey, and 
.sometimes even a bright yellow ; on which is 
disposed along the whole length of the hack 
a series of large, chain-like, reddish-brown, 
and sometimes perfectly red variegations, 
leaving large open oval spaces of the ground- 
colour at regular intervals: between these 
larger marks are disposed many smaller ones 
of uncertain forms, and more or less nume- 
rous in different parts. 
The boa constrictor is a native of Africa, 
India, the larger Indian islands, and South 
America, where it chiefly resides in the 
most retired situations in woody and marshy 
regions. 
It was, in all probability, an enormous spe- 
cimen of this very serpent that once diffused 
so violent a terror amongst the most valiant of 
mankind, and threw a whole Homan army 
into dismay. Historians relate this surprising 
event in terms of considerable luxuriance. 
Valerius Maximus thus mentions it from Livy, 
in one of the lost books of whose history it 
was related more at large. 
“ And since we are on the subject of un- 
common phenomena, we may here mention 
the serpent so eloquently and accurately re- 
corded by Livy ; who says, that near the ri- 
ver Bagrada in Africa, a snake was seen of so 
enormous a magnitude as to prevent the army 
of Attilius Hegulus from the use of the river ; 
and after snatching up several soldiers with 
its enormous mouth, and devouring them, 
and killing several more by striking and 
squeezing them with the spires of its tail, was 
at length destroyed by assailing it with all the 
force of military engines and showers of stones, 
after it had withstood the attack of their 
spears and darts : that it was regarded by the 
whole army as a more formidable enemy 
than even Carthage itself; and that the w'hole 
adjacent region being tainted with the pesti- 
lential effluvia proceeding from its remains, 
and the waters with its blood, the Homan 
army was obliged lo remove its station: lie 
also adds, that the skin of the monster, mea- 
suring 120 feet in length, w as sent to Home 
as a trophy.” 
The flesh of this serpent is eaten by the 
Indians and negroes of Africa, and they make 
its skin into garments. Plate Nat. Hist, 
fig. 50. 
2. Boa scytale, or spotted. The spot- 
ted boa is sometimes scarcely inferior in 
size 'o the constrictor, and is of simi- 
milar manners, destroying, like that animal 
goats, sheep, deer, &c. It is described as being 
generally of a grey or glaucous colour, 
marked with large orbicular black spots on 
the back ; and with smaller ones of similar 
form, but with white centres, on the sides : 
while on the abdomen are scattered several 
oblong spots and marks,- interspersed with 
smaller specks and variegations. It is a na- 
tive of several parts of South America, and, 
like other large snakes, is occasionally eaten 
by the Indians. 
3. Boa cenchris, or ringed. This also 
grows to a large size, though not equal 
to either of the former species, from 
which, as well as from most others, it may be 
easily distinguished by the Tegular distribution 
of its colours ; the general cast being ferru- 
ginous, darkest on the back, where it is 
marked by a continued series of very large 
blackish circles from head To tail ; while along 
the sjldes are interspersed several kidney- 
shaped blackish spots with white centres : 
the head is a lengthened form, and is marked 
by a black longitudinal and two lateral bands. 
This animal is a native of South Ame- 
rica. 
4. Boa enydris, or water. This spe- 
cies, according to Linnaeus, is variegated 
with different shades of grey ; the teeth in 
the lower jaw are longer than usu al in this 
genus ; the number of abdominal scuta is 270, 
and of the subcaudal ones 105. 
5. Boa orphryas or brown, mention- 
ed by Linnaeus from a specimen in the 
museum of Degeer : has the general 
habit of the B. constrictor, but is of a dark 
Or dusky colour, and has 281 abdominal and 
84 subcaudal scuta. 
6. Boa canina, a highly beautiful snake : 
measuring about four feet in length, 
and being of moderate size or thick- 
ness in proportion : the head is large, 
and shaped like that of a dog; the co- 
lour of the whole animal on the upper parts 
is a most beautiful Saxon-green, with several 
short, undulating, transverse white bars down 
the back, the edges of which are of a deeper 
or stronger green than the ground colour of 
the body : the under or abdominal part is 
white. This species is a native of South 
America. In the British Museum is an ele- 
gant specimen. 
7. Boa regia is, in the form of its head and 
the general shape of the body, most allied to 
the canina and phrygia. In its colour it ap- 
pears to vary, the ground-colour being white, 
but the variegations sometimes dusky or 
chesnut, and sometimes of a most elegant 
orange-red, accompanied by a tinge of blos- 
som-colour on the lighter parts. The head 
is covered in front with large scales : the tail 
is extremely short, and tapers suddenly. 
8. Boa phrygia. Among the whole serpent 
tribe it may be doubted whether there exists a 
species more truly elegant than the present. 
Its general size seems to be nearly that of 
the boa canina, but its length is rather 
greater in proportion : the ground-colour of 
the whole animal is white, with a very slight cast 
of yellowish-brown on the back, while along 
the w'hole upper part is disposed a continued 
series of black variegations, so conducted as 
to bear a striking resemblance to an embroi- 
dery in needle-work : the head is of the same 
form with that of the boa canina, and marked 
by three narrow black streaks, which, running 
along the top of the head and the cheeks, join 
with the embroidered pattern of the back. 
9. Boa hortulana is of moderate size, mea- 
suring only a few feet in length, and being of 
a slender form ; has obtained its Linnsean title 
from the singular variegations on the head, 
which are of a blackish brown on a pale fer- 
ruginous or yellowish ground, and in some de- 
gree represent the form of a parterre in an oid- 
lashioned garden : the variegations on the 
body are of similar colour, and are disposed 
into large circular, and sometimes angular 
patches on the sides. See Plate Nat. Hist. 
10. Boa murinais a middle-sized species, 
measuring about two feet and a half or three 
feet in length, and being of a moderately 
thick form: the colour of the whole upper 
part is grey or blueish-brown, w ith several 
moderately large round black spots dispersed 
in a somewhat irregular manner along the 
back and sides : the head is marked on each 
side by two longitudinal black stripes : this 
species is said to feed principally on rats, and 
to be found in South America. 
11. Boa crotaline is a native of Surinam, 
and is a large species, marked on the hack by 
a chain of black ihomboid spots, and is fur- 
nished with very large and strong fangs. 
12. Boafasciata. It is to Dr. Patrick Russel 
that we owe the knowledge of this remarkable 
species, which is a native of India, and is said 
to be most frequent in the country of Bengal. 
It is of a yellow colour, marked with pretty 
numerous dusky-blue transverse bands, con- 
tinued at equal distances : the head is rather 
small, and covered in front with large scales : 
the body is of a trigonal form, the sides sloping 
very considerably : the whole length of the 
animal is something more than live feet ; 
the diameter, in the thickest part, being 
nearly live inches : the length of the tail 
live inches only, and its termination rather 
obtuse. 
This snake is among the number of poi- 
sonous species, and its bite is considered by 
the Indians as inevitably fatal. A specimen 
was brought to Dr. Russel in the month of 
November, 1788, in an apparently weak and 
languid state, leaving been bruised in taking. 
Being set at liberty in a room, it crept slowly 
towards an obscure corner ; where a t hicken 
being presented to him he took no particular 
notice of it, and even suffered the bird to 
stand on his back. As he shewed no dispo- 
sition to bite, his jaws were forcibly opened, 
and the thigh of the chicken being placed be- 
tween them, the mouth was so closed over it 
as to oblige the fangs to act. The bird, when 
disengaged, shewed immediate symptoms of 
poi on, and after several ineffectual efforts to 
rise, rested with the beak on the ground, the 
head beingseized with trembling. In the space 
of twenty minutes it lay down on one side, 
and convulsions soon supervening, it expired 
within twenty-six minutes from the bile. 
13. Boa viperina is also an Indian species, 
first described in the work of Dr. Russel. It 
is about a foot and a half in length and of a 
moderately deep brown colour ; the baeje 
