BY THOMAS L. BANCROFT, M.B., EDIN. 253- 



of dragon-flies ; so helpless is it and so numerous its 

 enemies that I am of opinion not one individual ever 

 escapes in an ordinary season. In aquaria, it is extremely 

 difficult to prevent the liti ie fish from being devoured by 

 insects : so lar I have beer, unable from this cause to rear 

 fish longer than ten weeks • some of the insects live in the 

 stems of the water weeds and elude the most careful 

 detection ; yoa may daih- watch your Uttle fish thrive 

 right up to its disappearance when further search brings 

 to Ught a larva or a part of the fish's remains. 



It is probable that certain meteorological conditions 

 occur, perhaps once or t^nce in a century, during which 

 the enemies of the young Ceratoclus are removed. Such 

 a condition might occur in this manner ; during a pro- 

 longed drought when the Burnett River is reduced to 

 a chain of lagoons, the enemies would be absent ; the 

 enemies consisting of small fishes, prawns and insects, 

 live ]n the water weeds in comparatively shallow water,, 

 water ^to a depth of six feet or so ; now in a drought the 

 water would have receded past this level and the small 

 fish have been devoured by the larger ones, eels especially, 

 so that eventually only large fish remain ; a flood follow- 

 ing would give the Ceratodus freedom from its enemies, 

 possibly for a number of years. 



During a flood in an ordinary season all the httle 

 fish and insects keep well to the edge and go up gullies, 

 and when the water recedes return again to the same parts 

 of the river which they left. Large trees having been 

 undermined by the flood and falling into the river, are 

 the means of causing a considerable wash out, deep pools 

 or lagoons below the obstruction resulting ; such new 

 lagoons would be free from water weeds and it is possible 

 that a flood occuring in the winter might bring about 

 conditions favourable to the propagation of Ceratodus 

 in those new lagoons. 



As it is manifest that withotic assistance or unless 

 natural favourable conditions occur in the near future, 

 this interesting fish will shortly be extinct, endeavours 

 should be made at once to prevent the extinction. 



Mr. D. O'Connor, on behalf of this Society, which 

 received a subsidy from the Queensland Government 



