384 PROCEEDTNGS OF SECTION D. 



known as "school fish." Young- Sea Breams of the genus 

 Clirysophrijs, and of" which the Silver Bream, C australis, 

 is a Avell known Tasmanian representative, afford charac- 

 teristic illustrations of species that are distinctly cross-banded 

 until their arrival at about one-half of their adult size. The 

 so-called " Colonial Salmon," Arrvpis salar, a member of 

 the Perch family, and very abundantly i-epresented in Tas- 

 manian waters, is conspicuous in its half-grown state for the 

 series of gold-brown spots that decorate its sides. On a near 

 examination these spots are found to exhibit a distinct trans- 

 versely linear arrrangement. In the very young fish they 

 in part ])resent more or less the character of transverse lines, 

 wdiile in the largest adult individuals the spots or lines have 

 almost, if not entirely disappeared. Pish of this type of 

 ornamentation are esjjecially interesting as illustrating 

 transitory conditions between sim]>ly banded and diffusely 

 spotted species. The Common Toad fish, Tetradonhaniiltoni, 

 and the Kelp Fish, Chironemnsmarmoratns, may be cited as 

 familiar Tasmanian species in which transversely disposed 

 series of spots or blotches replace the, in all probability, 

 primarily distinct bands. 



Looking somewhat further afield than ihe Tasmanian Fish- 

 fauna, the number of species found to jiossess a transversely 

 banded plan of ornamentation in their young, and also very 

 frequently throughout their mature condition, is almost 

 bewildering. There is, in point of fact, scarcely a natural 

 family group from which some one or more members might 

 not be selected, w^hile in many instances it represents the 

 dominant plan of decoration. Commencing with that family, 

 the Percido', to which the fi"ont place is usually allotted in 

 icthyological classificatory systems, no fitter illustration could 

 probably be selected than the common English freshwater 

 Perch, Perca fiuviatilis, already aecliniutised in Tasmania 

 and Victoria. This fish, as it will l)e well remembered, is 

 most conspicuous for the series of broad black transverse 

 bands which decorate its sides throughout life, and render it 

 one of the most handsome of British freshwater fishes. The 

 Pike Perch, Lncioperca.. of the Northern European rivers, is 

 similarly ornamented. The true sea perches, represented by 

 the host of sjiecies referable to the genus Serranns, ov so- 

 called "Rock Cods,"' of Queensland waters, include a number 

 of forms in which from five to seven broad cross-bands are 

 conspicuously developed. These bands, moreover, are in 

 many instances under direct control, shining- with greater or less 



