10 THE ORDER OF SNAKES—OPHIDIA. 
and, by a little attention to the subject, this may be easily done. The 
following synopsis shews the distinguishing characters of— 
a.—Nown-venomous SNAKES. Blind Snakes. 
Scales smooth, polished, not imbricated ; without external eyes ; tail \ plate V, figs. 9, 9a, 
ing i i ee ..) 10,11, 12, 12a, 
very short, ending in a sharp point sie et apa, tha 
Colubrides and 
ore upper and Tree Snakes. 
Gape of mouth deeply curved upwards, seven or m pp Piste ¥, fsa 8, 64, 
lower labials 7, Ta, 8, 8a. 
Scales small, in more than thirty rows, more than ten labial scales Rdg cas 
bordering the mouth above and below ; tail short and prehensile; Plate V, figs. 9, 3, 
rudimentary limbs like spurs on each side of the vent ... on 3a, 4, 5, Ba. 
Innocuous snakes when they bite leave marks thus— 
6.—Venomous SNakEs. ; 
The gape of the mouth forming a straight line ; with upper and lower ces 
labial shields six, and never more than seven in number ; body- | Colubrine Snakes. 
scales in not more than twenty-six rows ; larger teeth in front of aa 4 and 
the upper jaw covered by the gums : 
Venomous snakes, when they bite, leave two punctures only, thus— 
An Australian snake that is not thicker than a man’s little finger, 
whatever may be its length, cannot by its bite endanger the life of an adult 
human being. 
Giinther states that “poisonous snakes are armed with a long 
canaliculated tooth in front of the upper jaw, with a duct which carries 
the poisonous fluid from a large gland to the tooth. This venom gland 
corresponds with the parotid salivary gland of the mammals, and is 
situated on the side of the head, above the angle of the mouth; it is 
invested by a dense fibrous sheath, which is covered by a layer of muscular 
fibres. At the moment the snake opens its mouth to bite, these muscles 
compress the gland, and force its contents through the excretory duct into 
the channel of the venom tooth, whence it is injected into the wound. 
The structure of the venom tooth is not the same in all poisonous snakes ; 
in some it is fixed to the maxillary bone, which is as long, or nearly as 
long as in the non-venomous snakes, and generally bears one or more 
ordinary teeth on its hinder portion. The venom tooth is fixed more or 
less erect, is not very long, and its channel is generally visible as an external 
groove. The poisonous snakes with this dentition, have externally a 
more or less striking resemblance to the non-venomous ones; and on 
