DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 829 



their long zig-zag processes being characteristic. Two or three extend over the whole 

 yolk- surface. The larva now measures 3^ mm. ; from the snout to the anus ly 1 ^ mm., 

 the tail being thus very long, viz., 2 T ^ mm. The lower lobe of the caudal fin appears 

 to "be larger than the upper. The envelope of the oil-globule is thickened, and pigment 

 appears in it. The greenish-yellow pigment-corpuscles are more numerous, and have 

 a well-defined oval outline. These corpuscles are clear and homogeneous in vigorous 

 examples, but they become granular in moribund and decaying forms ; moreover, while 

 the black chromatophores are elaborately stellate these remain amorphous or rounded. 

 The larval fishes shoot upward from the bottom of the vessel, and strive to reach the 

 surface with more or less success, then, hanging head downward, sink slowly to the bottom. 

 In their upward course the yolk-sac is inferior, but when the fish is motionless it turns 

 uppermost and the fish descends. 



On the sixth day after emergence (12th May), an indentation passes across the 

 nasal region, but in the earlier part of the day the mouth is not yet open, though a 

 fold of epiblast hangs like a curtain on each side. Later in the day the mouth appears 

 as a lenticular slit, cells defining its upper and lower margins. 



At the end of the first week of freedom (13th May) the larval fish measures 3^ 

 mm. (PI. XVII. fig. 10). The mouth is freely open. The eyes are deeply coloured 

 with black pigment. An opercular fold has grown over the cleft, leaving a fissure 

 behind and below the otocysts, which are now spacious and thin walled. The pectorals 

 still have a horizontal attachment, but can be elevated and depressed; and they show 

 radial thickenings (fin-rays). The yolk has much diminished, and has five or six large 

 stellate black chromatophores, but these do not extend beyond the yolk proper (in the 

 cortex), whereas the yellow spots occur all over the integument. A pericardial wall 

 appears, and the endocardial surface is rugose. The anus now opens (?) on the lower 

 margin of the fin, and the space between the anus and the oil-globule is large, as the 

 latter has been dragged forward by the wall of the diminishing yolk, but the globule itself 

 does not appear to be much smaller. Large black chromatophores occur over the mid- 

 brain, and a row of them begins near the root of the pectoral, and extends along the 

 dorsal region, ceasing above the anus. At the latter a line commences along the upper 

 margin of the notochord and ends a short distance from the tail, extending over § of the 

 caudal trunk. At its termination, a confused mass of elongated chromatophores trends 

 from the margin of the muscles outward over the tail-fin. A similar mass passes ven- 

 trally. A concentration of black pigment also occurs on the dorsal surface, behind and 

 above the otocysts. 



On the 30th August 1886 very young examples of the ling (PI. XVIII. fig. 3), about 

 8 '5 mm. to 9 mm. in length — resembling Phycis, were captured. Along the dorsum a 

 slightly greenish tint was observable, with minute scattered black pigment-spots. Two 

 well-marked black bars pass behind the abdomen, one a short distance posterior to the 

 latter, and another in front of the base of the tail. They are best developed ventrally, 

 and do not reach to the dorsum, while a pale brownish hue surrounds them. Under the 



