SCALES OF SOME AUSTRALIAN FISHES.— COCKE RE LL. 35 



THE SCALES OF SOME AUSTRALIAN FISHES. 



By T. D. A. Cockerell, University of Colorado. 



Through the continued efforts of Dr. R. Hamlyn-Harris, I am now 

 able to report on the scales of a number of additional Australian fishes, some of 

 them of more than ordinary interest. As before, it appears that with rare 

 exceptions the Southern species have scales closely resembling their Northern 

 congeners, when such exist. Although scales are very variable in certain 

 respects, their general characters are very constant, and persist while other 

 features of the fishes change, as for example in the Chaetodontidse mentioned 

 below. Dr. Hamlyn-Harris informs me that not all the species discussed in my 

 former contribution to these Memoirs (December, 1913) are from Queensland. 

 Holocentrus angustifrons comes from New Britain; while Pempheris multira- 

 ddatus, Cheilodactylus nigricans, and Eupetrichthys angustipes are Southern 

 species. 



ELOPIDiE. 



Megalops cyprinoides (Broussonet). Queensland. Scales 7-7-J mm. 

 broad, 6-7 long; formed as in Tarpon atlanticus, with even more deeply 

 scalloped basal margin; basal radii about 7; laterobasal angles rounded; 

 nucleus above the middle ; apical margin very thin, with very numerous 

 evanescent radii, but the distinct apical radii arising from the nucleus are only 

 one or two, extremely variable and irregular, often branching; there are also 

 sometimes lateral radii, one on each side, which may branch, and there may 

 be formed an approach to an irregular network, not well defined, but indi- 

 cating a condition exhibited by some species of Barous. The cireuli in the 

 region above the nucleus are broken into minute tubercles; those below the 

 nucleus are more or less evidently beaded. 



These scales are essentially as in Tarpon, differing by the small size and 

 greater number of basal radii. The basal cireuli are much more regular and 

 less crowded than in Synodits. 



DOROSOMATHXE. 



Dorosoma come Richardson. Queensland. Scales 5^-6 mm. broad, 5-5^ 

 long ; base with a bow-like (with double curve) outline ; cireuli very fine, 

 wholly transverse ; apical field very thin, without cireuli, no apical teeth ; radii 

 about 12, transverse, rarely branching. The radii are more or less bent or 

 obtusely subangulate in the middle, but not at all interrupted. The median 

 lateral cireuli and radii reach the margin at right angles. 



