THE PRINCIPAL SPECIES OF POISONOUS SNAKES 87 
Seven species of this genus are known, divided into two groups 
as follows :—. 
(1) Scales on the body in 15 rows. 
D. psammophis (fig. 47).—Internasal shields at least half as 
long as the præfrontals. 
D. torquata. — Internasals 
more than half as long as the 
prefrontals. 
D. olivacea (fig. 48).—In- 
ternasals not more than half 
as long as the prefrontals ; 
snout broad. Fic. 50.—Diemenia nuchalis. 
(2) Scales in 17 or 19 rows. 
D. modesta.—154—165 ventrals. 
D. textilis (Brown Snake, fig. 49).—190—232 ventrals. 
D. nuchalis (fig. 50).—184—224 ventrals. 
(e) Pseudechis. 
Maxillary bones extending forwards as far as the palatines, 
5 small 
solid teeth ; anterior mandibular teeth long. Head distinct from 
the neck; eyes rather small, 
with a pair of large grooved poison-fangs followed by 2 
with round pupils; nostril be- 
tween two nasal shields. Body 
cylindrical. Scales smooth, in 
li, 
neck). ‘Tail moderate; sub- 
23 rows (more on the 
caudals in 2 rows, or partly geo cc Den ee 
single, partly in 2 rows. Fia. 51.—Pseudechis porphyriacus. 
Total length, 1,500—2,000 
millimetres, sometimes more. 
Habitat : Australia and New Guinea. 
This genus includes eight species. 
