114 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV' 



In Australia HonlocephaJus curtus, H. superbus, and Pseudechis are the 

 "worst. The sea snakes rarely attack man, though so common in Australia 

 and waters of the Far East. 



Anatomical Characters. — The " true vipers " are distinguished by their 

 triangular-shaped head and constricted neck ; the scales on the head are 

 generally small, the loreals (scales between the nasal and anterior ocular) 

 are almost always wanting. The pupil is vertical ; the fangs are tubular, 

 large ; reserve teeth being present, but no others are found on the short 

 maxillary bones ; the tail is rapidly attenuated. 



The " pit vipers " have triangular heads, but with large scutes on the top ; 

 otherwise as in the true vipers, the poison faDgs are very large, the maxillary 

 bones are small and very movable, and the tail ends in a rattle or hard spine. 



The poisonous Colubrine have smaller heads of regular shape ; the scutes 

 t>n the top are generally well-marked and regular ; the " loreals " are usually 

 absent ; the maxillary bones are longer, less movable, and the fangs smaller 

 than in the vipers, and they are grooved along the anterior border and not 

 tubular. The pupil of the eye is generally round, and the tail gradually 

 tapers to a point. 



The Hi/drophidae, or sea snakes, have small heads, with the nostrils on 

 the upper surface. The anterior frontal scutes and loreals are absent, the 

 pupils are round, the ventral shields are usually absent, and the tail is 

 flattened from side to side, the tongue is short, and the poison fangs are 

 small and grooved. 



The great distinction between non-venomous and poisonous snakes is that 

 the former possess two complete rows of small ungrooved teeth on either 

 side of the upper jaw, the outer row, twenty to twenty-four in number, 

 being attached to the maxillary bones, the inner to the palatine ; when they 

 bite, they leave characteristic marks. 



In poisonous snakes the outer row is represented by one or more tubular 

 or grooved fangs, firmly ankylosed to the maxillary bone, which is freely 

 movable; this mobility allows the erection and depression of the fangs. The 

 anterior is always the largest, the others, if present, being reserve teeth. 

 "When these snakes bite, they leave usually two punctures only. 



The Venom is secreted by a compound racemose gland, which Gunther 

 describes as being homologous with the parotid glands of mammals, having 

 large alveoli which act as receptacles for the fluid ; these glands are placed 

 behind the orbit above the angle of the mouth ; they are invested with a 

 dense fibrous sheath, being also covered by the masseter muscles. The 

 excr3tory duct passes forwards, opening into the base of the sheath of 

 mucous membrane covering the fang, being heie bent at an acute angle, so 

 as to face the front border of the tooth, thus allowing the fluid to flow freely 

 down the tube or groove as the case may be. When the snake opens its 

 mouth to bite, the muscles act on the maxillary bones and erect the fangs ; 

 as the jaw closes on the part bitten, the masseter and pterygoids compiess 



