Anderton. — Ohservations on Ne2v Zealand Fishes. 481 



250,000 ova have been collected this year, and 217,000, or 

 868 per cent, of larvae, hatched. 



Some two dozen of the stock fish in the pond have suc- 

 cumbed at various times, and there is every reason to believe 

 that the cause of death may be attributed to their removal to 

 shallower and colder water, and that the long retardation and 

 non-extrusion of the eggs has caused these fish to sicken and 

 die. Many of the females still retain their eggs, and it is ex- 

 pected that large numbers will be collected before long. The 

 results from fish confined in the ponds up to the present have 

 been very poor, a very heavy handicap being the small range 

 of tides in these waters, and the consequent shallow ponds 

 with extremes of temperature. The best results were obtained 

 from the (evidently) late-spawning harbour flounders, and it 

 will probablv be found expedient to secure a .stock of small 

 immature fish and allow them to become acchmatised to the 

 extremes of temperature experienced in the ponds. There are 

 at present a few such fish, from 4 in. to 5 in. long, which are 

 probably about three years old. 



On the 8th August 283,000 ripe eggs were taken from a smgle 

 flounder {R. plebeius) on board the trawler, and all were success- 

 fully fertihsed. The egg (Plate XVIII, figs. / and g) is buoyant, 

 and is very minute, being only 0-65 mm. in diameter, v/ith from 

 eight to thirteen small oil-globules. The larvae (figs, c and d) 

 hatch in five days at an average temperature of 9° C. The 

 newly hatched larvae are fairly active, and are almost trans- 

 parent, with bright-yellow and black pigment markings. The}^ 

 are perfectly symmetrical, but are at first unable to see or feed, 

 though they appear quite conscious of the presence of a dip- 

 ping-tube or other instrument when placed near them. They 

 are provided with a comparatively large yolk-sac containing 

 the albumen on Avhich they subsist until able to forage for them- 

 selves. The oil-globules remain in the yolk-sac after hatching. 

 By the fifth day (Plate XIX, fig. h) the yolk-sac is almost 

 absorbed, the eyes and mouth are open, and the larvae are able 

 to seek out their own particular sustenance. 



R. tapirina : The ova of this species is considerably larger 

 than that of R. pleheia, being 0-8 mm. in diameter, and it contains 

 a single large oil-globule of a light-orange colour. The larvae 

 hatch in five days, as with the other species, but they are much 

 larger and more active. No drawings were made of either eggs 

 or larvae, as no fish were kept in the ponds this year. 



The Sole {PeltorJiamphus novce-zealandice). 

 ' From the irregular nature of the observations made on this 

 fish, which is commonly known as the English sole, it is not 

 16— Trans. 



