303 



granulated at its front and hind-border. Base of adipose fin a 

 little less than that of dorsal, 2 ! / 2 to 3 times (in adult speci- 

 mens) in its distance from that fin. Height of anal equal to 

 postorbital part of head, ventrals scarcely shorter and not or 

 scarcely reaching anal. Pectorals pointed, as long as the head 

 without snout, their flattened spine one eyediameter shorter, 

 its frontborder feebly and its hindborder strongly serrated or 

 granulated, about as long as that of the dorsal. Caudal deeply 

 forked. Axillary pore present. Villiform teeth in an arcuate 

 band in the jaws, 

 in 4 patches on the 

 palate, the two oval 

 median ones their 

 own diameter apart 

 and separated from 

 the two outer late- 

 ral ones, which are 

 slightly curved and 

 3 times as broad as 

 long. 9 stiff, broa- 

 dened and pointed 

 gillrakers, decreas- 

 ing in size anteri- 



Fig. 127. Arius acrocephalus M. Web. 



orly, the longest equal to length of branchial filaments. Silvery, 

 upper surface of head and body bluish grey, dorsal and caudal 

 with black edgings, sometimes the entire lobes of lastnamed 

 fin blackish. Length about 240 mm. 



Habitat: South New Guinea (Lorentz river!). 



In tidal reach of river and above it. 



20. Arius leptaspis (Blkr.). 



Hcxanematichthys leptaspis Bleeker, All. Tchth. II. 1862, p. 27. 

 Ariiis leptaspis Max Weber, Nova Guinea V. livr. 2. 1908, p. 227. 

 Arius leptaspis Max Weber, Nova Guinea IX. livr. 4. 1913, p. 544. 



B. 6; D. I. 7: A. 4. 15; P. I. 9; V. 6. 



Elongate; height under the dorsal spine somewhat more 

 than 5. Head about 3'/ 2 , much broader than high, its width 

 about '/o shorter than head. Headshields corrugate ; occipital 

 process triangular, longer than broad at its base, its rather 

 broad, truncate hindborder touching the narrow, crescentic 

 basal bone, mesially with a longitudinal, blunt elevation. 



