302 
Teeth on the vomer in two slightly separated, oval patches, 
contiguous with the palatine patches, which are rather more 
than twice as broad as antero-posteriorly long. 16 stiff, trian- 
gular gillrakers, ventrally decreasing much in length, the longest 
about equal to branchial filaments. Brown-grey above, silvery 
below and on the sides. Fins yellowish, margin of caudal 
dark. Length over 260 mm. 
Habitat: South New Guinea (Fly river!; Lorentz river!). 
In tidal part of rivers. 
19. Arius acrocephalus M. Web. 
Arius acrocephalus Max Weber, Nova Guinea IX. livr. 4. 1913, p. 543. 
B. 6; DM: i275 A117 Pa a a Nee: 
Elongate. Height below dorsal spine 4'/,, head about 3'/,, 
its width about 1'/, times in its length. Dorsal profile sloping 
steeply to the snout in a straight line, with exception of a 
feeble convexity above the opercles. Headshields with feeble, 
granulated lines. Occipital process with slightly convergent 
straight sideborders, its truncate hindborder touches the semi- 
circular basal bone 
of the dorsal spine, 
its width at base 
W/, in its leneth: 
Rhombic median 
fontanel elongate, 
reaches to the last 
1] ef, headJowhe 
broad, short hume- 
ral process with 
reticulate ridges. 
Eye 6-6'/,, almost 
3 times in the inter- 
orbital space, more 
Fig. 126. Arius acrocephalus M. Web. 1). than 2 times in the 
prominent snout, 
which is '/, of length of head and which is shorter than the 
curved gape. Lips thin, only prominent at the corner of the 
mouth. Maxillary barbels do not reach base of pectorals, 
mandibulary ones to hindborder of the gillmembrane, mental 
ones '/, shorter. Height of dorsal more than head without 
snout, its spine scarcely longer than postorbital part of head, 
a ee ae 
