DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 863 



being thus somewhat spindle-shaped. The snout is comparatively blunt, and the large 

 size of the eye gives a resemblance to the condition in the Gadidse, and to some extent 

 also to that in the Pleuronectidse. The auditory capsule is large, a prominent elevation 

 of the outline occurring in the region. The jaws present the proportions in the groups just 

 mentioned. The action of the heart is readily seen through the large opercular aperture. 



The body is elongate, about 7 mm. in length, the tapering extremity of the notochord 

 being bounded by a somewhat lanceolate embryonic fin, in which the rays (embryonic) 

 are developing next the base. The abdomen presents a marked incurvation in front of 

 the rectum, and the anus is prominent. The pectorals are large and fan-shaped. 



The pigment is mainly of two kinds, viz., grass-green and black. The head shows 

 black pigment over the otocysts, black and green in front of the eye, and on the branchial 

 and mandibular regions. From the posterior margin of the opercular aperture to the base 

 of the pectoral the same pigments occur. The pectorals have regular rays of similar pig- 

 ment — tinged with pale greenish. The abdomen is covered with black and green pigments. 

 The dorsal and ventral edges of the body have a series of black pigment-corpuscles, the 

 former extending from behind the pectoral to the last vertical bars of the dorsal marginal 

 fin, as shown in the sketch; while the latter extend from the vent to the narrow part of 

 the tail. When viewed from the ventral aspect, a broad bar of pigment stretches between 

 the pectorals, and a considerable quantity is scattered over the abdomen. In a smaller 

 specimen the opercular fold is rendered distinct by the black pigment in front of it, and 

 the pale region behind it. The deep parts of both dorsal and ventral areas of the mar- 

 ginal fin have peculiar vertical streaks of greenish, and rows of black pigment-corpuscles. 

 These touches are generally slightly curved, and appear to form two groups in each fin, 

 a feature especially seen in the dorsal. The tail is faintly tinged with green. 



The gall-bladder is deep green ; the oil-globule is colourless. 



In the mid- water net, on 9th April, a few miles from shore, the next stage, fully 6 mm. 

 long, appeared. In spirit it presents a few black chromatophores on the cheeks, and the 

 bases of the pectorals show the black pigment-rows present in the older stage (PI. XVIII. 

 fig. 11). The sides of the body from the tip of the pectorals backward almost to the 

 tail show a series of isolated black chromatophores arranged in a double row, toward the 

 dorsal and ventral edge. A group of similar pigment-corpuscles characterises the median 

 or wide part of the marginal fin dorsally and ventrally. On the sides and ventral surface 

 of the abdomen the same black chromatophores are scattered, and they run along the 

 ventral surface to the base of the tail. 



The marginal fin has expanded dorsally and ventrally in the median line, but only 

 embryonic fin-rays occur in it. A slight narrowing dorsally and ventrally is evident in 

 front of the tail, which also shows embryonic rays. The anus is very prominent, and in 

 front of it another projection of the edge occurs — a feature characteristic of the form. 

 The large pectorals likewise show only embryonic rays, and the lines of black pigment 

 spring from the distal edge of the basal process. The notochord is quite straight. 



The next stage observed was an example five-eighths of an inch in length, procured in 



