scal:es of some austbalian fishes.— cockebell. 
45- 
than long ; lower margin wavy but not crenate ; laterobasal corners obtuse, but 
often projecting, the lateral margins then concave ; no radii ; cireuli rather coarse^ 
transverse as far as an obtuse ridge which extends on each side from nucleus to- 
laterobasal corner, then bending and ascending vertically at sides ; nucleus just 
below the apical margin; margin with large, very sharp teeth (about 24), and 
rows of similar teeth usually (not always) present in the submarginal region,, 
whence they are easily deciduous. There is no ctenoid patch of the ordinary type.. 
S. multifasciatus, as figured by Gunther, has similar teeth. 
This is a very remarkable type of scale, rather suggestive of Fercopsis,- 
In Colunibia transmofitana (U. S. Nat. Mus.) the scales are very broad, and have 
a subapical nucleus, and a single (never more than one) rov/ of large and sharp 
apical teeth (about 20-24) ; they also are without radii. The scale of Columbia 
is much broader than that of Scatophagus, the sides are very much shorter, and 
the eirculi are not so dense. 
PLATACID^. 
Platax teira Forskal. Queensland. Scales subquadrate, as broad as 
long, or broader than long, diameter about 2^-3 mm., peculiar for the contracted 
base, so that the sides converge downwards; laterobasal corners very obtuse; 
basal radii 3 or 4, very distinct, but close together ; circuli fine, normal ; nucleus 
subapical, just below the ctenoid patch, which is only 3 or 4 rows deep ; marginal 
teeth long and sharp ; submarginal elements shaped like tree-stumps, distinctly 
longer than broad. 
This resembles Scatophagus in the subapical nucleus, but is otherwise 
very different. Some scales of Pomacanthus arcuaius show the contracted base 
very well. 
CHJ^TODONTID^. 
The species now before me may be separated into three groups as follows : — 
Median ribs of apical teeth extending as continuous rods to base of ctenoid area 
Pomacanihus arcuaius. 
Ctenoid patch large, vdth the elements separate, as usual in Aeanthopterygian scales . . 1. 
1. Seales much longer than broad, parallel-sided; nucleus subapical, just below the ctenoid 
patch; basal radii 6 to 8; eirculi excessively fine; ctenoid elements like those of 
Chcctodon (Queensland) . . . . . . . . . . Microcanihus strigatus Langsd. 
Scales not longer than broad, usually broader than long CJiwiodon, Chelmon, and TleniocJius. 
It is impossible to find satisfactory characters for the separation of the 
species of Chcetodon, Chelmon, and TleniocJius. The ctenoid elements of CJielmon 
are coarser than those of HenioeJms, but the structure is the same. The scales 
of these fishes must be easily deciduous, judging from the large number of 
latinucleate ones. 
