SERPENTS. 



383 



ing from it in having the ventrals deeply cut out on each side, is IT. stephensii, which 

 inhabits the neighborhood of Hastings Eiver. IT. coronoides is peculiar to Tasma^ 

 nia. H. nigrescens is unique in having the tongue vrhite. Though first only found 

 around Port Jackson, it has since been obtained from points along the coast further 

 north. It is closely allied to Vermicella, like which ophidian it allows itself to be 

 handled without offering resistance. 



Tropidechis carinata resembles in many points the members of the previous genus, 

 but has the scales keeled, which peculiarity, with others, gives it the appearance of 

 some harmless Tropidonotus picturatus, from which animal, however, it can be easily 

 separated by counting the number of rows of scales, the venomous snake having 

 twenty-three rows, while Tropidonotus has only fifteen. 



Fig. 222. — Callophis macellandi and C. annularis. 



It has been noticed that venomous snakes often have the temporal shield inserted 

 between the two last upper labials ; this arrangement is illustrated by the genus just 

 treated. 



The genus JPseudecMs has the scales arranged in seventeen rows, the anterior sub- 

 caudals entire, while the hinder ones are generally divided ; behind the grooved fangs 

 are smaller simple teeth. The first species, P. porpliyriacim, a black snake, grows to a 

 length of six feet and is the most common Australian venomous snake, and was first 

 classified with the cobras by the early writers, being, as already said, one of those 

 ophidians which on irritation expand the skin of the neck. It is fond of moist locali- 

 ties, and is quite active when in the water, where it catches frogs, insects, and small 

 mammals ; as many as sixteen young water-rats {Hydromys leucogaster) have been 

 taken from its stomach. The bite is extremely venomous, soon producing the death 

 of a fair-sized animal. It is found all over Australia, but has never been captured in 

 Tasmania. 



