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weight of 10 lbs. The average weight, however, runs from 

 3 to 4 lbs., except in the North Esk, where they run smaller 

 than elsewhere. Mr. Brown and others who have observed 

 our freshwater fishes closely, assert that they cannot dis- 

 tinguish the male from the female, although they have 

 purposely opened hundreds of them. I have opened a good 

 number myself, but at the time I did not know of this fact, 

 and naturally supposed that they were ordinary females. I 

 am inclined now to consider that they are bisexual, and will 

 take the first opportunity to enquire into this matter more 

 fully. Unfortunately, the specimens in my collection have 

 the intestines removed. Blackfish are sometimes taken in 

 the brackish water of tidal rivers. 



Anguilla Australlsy the Common Eel ol Australia and 

 Tasmania, is very abundant in all our rivers. Large num- 

 bers are caught in the Tamar and its principal tributaries, 

 the North and South Esk. Some of the eels have been 

 taken in the Ringarooma and South Esk Rivers over 80 lbs. 

 in weight, and over 20 inches in girth. The market supply 

 could be greatly extended if there were any demand for 

 them. 



Prototroctes marcena, the Freshwater Herring, or 

 Cucumber Fish, although rarely exceeding ^ lbs. weight, 

 and 12 inches long, is perhaps the finest of our native 

 freshwater fishes. It has an adipose fin, and is closely 

 allied to the true Salmonoids of European waters. It is to 

 a certain extent migratory ; but whether it approaches the 

 lower reaches of the streams to spawn in suitable i*edds, or 

 whether it is necessary to approach the brackish water for 

 some other reason, is not yet quite clear. They are stated 

 by Mr. Brow^n to have been found in brackish water in the 

 Tamar a considerable distance belovv- the confluence of 

 the North and South Esk Rivers. The\ are a clean cut, 

 handsome shaped fish, with small head and elongate body, 

 like a diminutive salmon. They are chiefly insect feeders, 

 and during the season they at one time could be caught in 

 vast numbers in nearly all our rivers. Although in many 

 of our streams they appear to be again on the increase, 

 it is remarkable that about 14 years ago they suddenly 

 almost disappeared from most of our rivers where they 

 were formerly plentiful. The general conclusion is that 

 this disappearance of the herring was due to a wide spread 

 epidemic. In some places it is stated that thousands of 

 dead fish were seen floating down the rivers. The fins, eyes, 

 and gill-covers appeared to be covered Avith a fungus. It is 

 therefore likely that at particular periods they are subject to 

 the widespread attack of some species of Saproleg?iia, 



