_Habitat_: Australia and New Guinea. This genus includes eight species. (1) _P. porphyriacus_ (Black Snake; fig. 51).--Frontal shield longer than broad; 180-200 ventrals; 50-60 subcaudals. Colour black on the back; outer row of scales red at the base; ventrals red, edged with black. (2) _P. cupreus._--199-210 ventrals; 57-72 subcaudals. Colour coppery above, brown or orange below, all the scales and shields edged with brown. (3) _P. australis._--199-220 ventrals; 57-70 subcaudals; frontal shield once and two-thirds to twice as long as broad. Colour pale brown on the back, yellowish on the belly. (4) _P. darwiniensis._--Frontal as broad as long; 212 ventrals; 54-64 subcaudals. Colour reddish-brown; head pale brown; belly yellowish-white. (5) _P. papuanus._--Scales in 19-21 rows (26 or 27 on the neck); 221-224 ventrals; 49-55 subcaudals. Colour uniform black; chin white. (6) _P. scutellatus._--Subcaudal shields in 2 rows; scales on the body in 23 rows (25-30 on the neck); 230-233 ventrals; 61-78 subcaudals. Colour pale brown or dark brown; snout and cheeks pale brown or yellowish; belly yellow. (7) _P. microlepidotus._--30-36 scales across the neck, 23 across the middle of the body; 232-237 ventrals; 61-66 pairs of subcaudals. Colour dark brown on the back, yellowish-grey on the belly; head sometimes blackish. (8) _P. ferox._--Snout very broadly rounded. Scales on the body in 23 rows; 235 ventrals; 60 pairs of subcaudals. Colour black above, yellowish beneath. (f) =Denisonia.= Maxillary bones prolonged as far as the palatines, with a pair of large grooved poison-fangs, followed by 3-5 small solid teeth; anterior mandibular teeth greatly developed. Head fairly distinct from the body; eyes small, with round or vertically elliptic pupils; nasal shield entire or divided. Body cylindrical; scales smooth, in 15-19 rows; tail moderate or short; subcaudals in a single row, except in one species. According to the British Museum Catalogue, the genus _Denisonia_ includes twenty-one species, the principal characters of which are as follows:-- [Illustration: FIG. 52.--_Denisonia superba_ (The Copperhead).] (1) _D. superba_ (The Copperhead. Fig. 52).--Scales in 15-17 rows; nasal shield entire, in contact with the præocular; ventral scales 145-160; subcaudals 41-50. Colour brownish to dark olive on the back, often yellow or salmon-red on the sides; belly yellowish or greyish-olive. Total length, 1,010 millimetres; tail 160. _Habitat_: New South Wales, Southern Australia, Tasmania. (2) _D. coronata._--Scales in 15 rows; 138-151 ventrals; 38-51 subcaudals. [Illustration: FIG. 53.--_Denisonia coronoides._] Colour olive, with a black streak on each side of the head; belly yellowish or pale olive. Total length, 480 millimetres; tail 95. _Habitat_: Western Australia and New South Wales. (3) _D. coronoides_ (fig. 53).--Scales in 15 rows; 136-151 ventrals; 39-57 subcaudals.