FISHES—PHENOMENAL AND ECONOMICAL. 157 
group just without the pale of the true Gadide, with which it would otherwise be 
most naturally associated. With respect to the rudimentary development of the spinous 
rays, Gadopsis, in addition to its other points of interest, may be regarded as a form 
that bridges over, in a natural manner, the hiatus that is supposed to subsist between 
the ordinary spine-finned (Acanthopterygii), and spineless-finned (Anacanthini) fishes.. 
In this direction it would appear to the writer that additional transitional forms, 
apparently now extinct, probably united this abnormal Anacanthinoid with such 
Percoids as Oligorus and other allied Australian genera characteristic of the Murray 
river and its tributaries. Several of these share with Gadopsis a peculiar excavated 
contour of the frontal region of the head; the ventral fins, though not jugular, are 
set far forward, and have two filamentous prolongations, as commonly obtains 
among the true Gadide. ‘The peculiar pattern markings of Gadopsis are, it may be 
further remarked, wonderfully similar to those characteristic of the Murray Cod, 
Oligorus macquariensis, consisting of a series of darker scribblings and reticulations 
on a ground colour of olive or golden green, but which are scarcely, if ever, precisely 
alike in two specimens. This colour pattern, in Gadopsis, becomes speedily obliterated 
after death, leaving the fish a uniform black hue, from which it takes its characteristic 
popular title of the “Black-fish.” In the case of the Murray Cod, Oligorus, the circum- 
stance that the foregoing vernacular name should have been relegated to it serves to 
accentuate the fact that, setting aside the presence of its spinous fins, it presents to 
the eye of the uninitiated much in common with the external aspect and configuration 
of the common Cod. This last suggestion is necessarily not adduced as a serious 
argument respecting the possible affinities of the fish under discussion, but merely as a 
floating straw indicative of the existence of a probable strong current of positive 
evidence that may be found flowing underneath. 
It is a peculiarity of the distribution of Gadopsis marmoratus in Tasmania that, 
in common with the large fresh-water lobster, Astacopsis Franklini, it is indigenous 
only to those rivers which flow northwards and discharge themselves into Bass’s 
Straits and does not occur naturally in all of these. This fish has been artificially 
introduced from the St. Patrick’s to the South Esk, one of the northern rivers 
hitherto deficient in that species, and has since multiplied and thriven therein, showing 
that there were no special conditions existing that were inimical to its previous 
establishment in that river. Still more recently, the writer, acting in his capacity of 
Superintendent and Inspector of Fisheries to the Government of Tasmania, successfully 
transported to and established the same species in, the River Derwent, whence 
