286 THE VIVARIUM. 
near relative just mentioned, it should be provided with artificial 
heat while in captivity im this country. This Snake is generally 
rather spiteful, and it consequently does not very readily become 
tame. It is fairly hardy. 
P. sibilans is variable as to its colouring, e.g. : 
(1.) The back is brown, with a very narrow band running down 
the middle: the sides are olive, and bounded below by a 
broadish yellow streak. 
(2.) Like No. 1, but wanting the thin yellow dorsal line. 
(3.) Back and sides uniform brown, with the exception of a 
yellow line on each side, just above the ventral scales. 
(4.) Brown above, and yellowish below. 
In other respects P. sibilans is very similar to P. crucifer. 
The Hissing Sand Snake may sometimes be bought in London 
for about 10s. 
The Lacertine Snake (Celopeltis lacertina) is a native of most 
of the countries bordering upon the Mediterranean Sea. It may 
be easily recognised by the concavity or grooving of the crown of 
its head, by a groove before the eye, by its very long and narrow 
vertical shield, and by its lanceolate scales, which are grooved 
longitudinally. The upper parts of this Snake’s body are 
greenish-brown, either uniform or marked with rows of dark or 
black spots ; the under parts are yellowish. 
The Lacertine Snake is a very handsome reptile, and hardy 
enough to be kept in this country during the summer months 
without artificial heat. Its food should consist of lizards. I have 
found it to be very gentle. It may be bought in London, when 
in the market, for from 5s. to 9s. 
The Cape Bucephalus (Bucephalus capensis) is a very beautiful 
Tree Snake, and a native of the Cape of Good Hope. One of its 
chief attractions consists in an exceedingly large eye, possessing 
around pupil. It has a short, very thick head, distinct from 
the neck. Hence, of course, its generic name. It also possesses 
one loreal, one prze-ocular, three post-oculars, and seven upper 
labials. 
The coloration of this Reptile is rather variable. For 
example, it may be (1.) green above, and very pale green 
below; (2.) a dark olive above, and greenish-yellow beneath ; 
