Andekton. — Observations on Neiv Zealand Fishes. 479 



pectoral fins appear to be chiefly used as a means of locomotion, 

 assisted by a sharp wriggling motion of the body. Little change 

 takes place until about the sixth day, by which time the eyes 

 and mouth are open, the yolk-sac absorbed, and the little fish 

 may be seen actively pursuing the minute organisms on which 

 they feed. A few were reared until the twelfth day in a small 

 aquarium jar, by which time they had begun to assume many of 

 the characteristics of the adult fish. The pectoral fins are very 

 prominent, and the three lower rays, although showing promin- 

 ently, are still connected with the upper portion of the fin. It is 

 interesting to note that the gradual disappearance of the colour 

 in the oil-globule has been observed in Great Britain in the eggs 

 of Trigla gurnardus and T. cuculus. 



The Brill {Caulopsetta scapha). 



This fine fish appears to be only an occasional visitor ; it is 

 seldom taken on the trawhng-grounds off Otago Heads, and only 

 in small quantities. It is a very handsome fish, and is greatly 

 esteemed as a table delicacy. Nothing is at present known of 

 its habits and movements, but it is a fish deserving every possible 

 attention. Single ripe females have occasionally been taken, 

 but, in the absence of males, the eggs were not fertilised. But 

 on the 8th August of this year a small number were fertihsed, as 

 an experiment, with the milt of the sole {Peltorhaniphus novce- 

 zealandice). These were taken to the station, and all were found 

 to be fertihsed. Development proceeded favourably until the 

 11th, when these, along with many other eggs in the boxes, were 

 killed during a frosty night, and the interesting experiment of 

 hybridizing these fish could not be followed up, but may be 

 attempted on a future occasion. 



On the 17th August a few thousand of the eggs were success- 

 fully fertilised by Mr. Baird, engineer of the trawler " Express," 

 and were sent to the station. The egg (Plate XIX, fig. c) is 

 the largest of any of the local Pleuronectidce, being 11 mm. in 

 diameter. It is of the usual spherical form, transparent, and 

 buoyant, and contains a large laumber of oil-globules evenly 

 dispersed over the entire egg. It hatches at a mean temperature 

 of 5-5° C. in five days. 



The newly hatched larva (Plate XIX, fig. e) is at first very 

 inactive, generally floating helplessly on the surface of the water. 

 The oil-globules remain in the yolk-sac after hatching, and the 

 yellow pigmentation is very conspicuous. Owing to pressure of 

 other work these larvae were only kept for a few days, and no 

 further drawings were made. The larvae are easily identified by 

 their large size, their colour, and by the peculiar extension over 

 the head of the rudimentarv dorsal fin. 



