io 
NEW OR LITTLE KNOWS FISHES 
in the comparative broadness of the nuchal shield, the length of 
which is only twice its width ; in the more pronounced occipital 
granulation ; the stronger dorsal spine ; and the increased number 
(20 or 21) of anal rays. 
Prom the only other Australian species, Tacky sw us meyenii* 
it differs as follows : — 
a. Head large, J or more than ^ of the total length ; vomerine teeth in small 
number, deciduous; palatine patches subovate, about twice as long as 
wide, the tips not divergent posteriorly ; nuchal shield coarsely granu- 
lar ; dorsal buckler narrow; anal fin not higher than long; caudal fin 
shorter than the head broadbenti. 
cm. Head small, f or less than f of the total length ; vomerine teeth in 
moderate number, permanent ; palatine patches elongate and curved, 
about 4 times as long as wide, the tips divergent posteriorly ; nuchal 
shield smooth, or nearly so ; dorsal buckler rather wide ; anal fin higher 
than long ; caudal fin longer than head meyenii. 
NP] M APTE RYX iron . nov. 
Lateral line without anterior granulation. Head moderately 
depressed, wider than deep. Mouth rather large, crescentic, the 
upper jaw projecting and of normal width ; no rictal lobe. Jaws 
with bands of villiform teeth ; roof of mouth with villiform teeth 
on the vomer and palatines, the groups separate. Posterior nasal 
orifices not connected by membrane. Maxillary barbels long and 
slender. Eje rather small, lateral, with partially adnate lid ; a deep 
preorbital cavity. Dorsal buckler rather large and subcruciform, 
continuous with the nuchal shield. G ill-openings moderate, wider 
than the isthmus ; six branchiostegals, the first not dilated ; gill- 
rakers short and stout, in moderate number. Axillary pore minute. 
Payed dorsal fin opposite to the space between the pectorals and 
ventral s, the first ray produced in a long filament ; adipose fin 
rather large, inserted wholly above the anal. Occiput rounded ; 
nuchal crest strongly developed. Occipital fontanelle narrow ; a 
temporal foramen, [vrj/J-a, a thread ; irrepv^ a wing or fin.] 
Type Arias stirlingi.^ 
Northern and North-Eastern Australia. 
The position of the genus would^naturally fall between Hexane- 
matichthys and Hemiarius. 
* Ariodes meyenii Mliller & Troschel, Horse Ichth., iii, p. 9, 1849. Hab. Java. 
Singapore, Celebes. 
f Ogilby, Proc. Linn. Soc. N.S. Wales, xxiii, 1898, p. 281. 
