43 
ROCK COOK. 
prominently on the top of the head; first plate of the gill- 
covers minutely serrated; a row of prominent mucous orifices 
round the posterior half of the eye. Cheeks and body covered 
with large scales. The lateral line first rises, and near the tail 
drops again. Dorsal fin with seventeen firm and eight soft 
rays, the last double, with a slight sulcus under it; anal fin 
with five firm and seven soft rays, the last also double; 
ventrals six rays, of which one is firm, the fin partly fastened 
down with a membrane. Pectoral fin round, thirteen rays; 
tail nearly straight. Scales on the roots of all the fins except 
the pectorals. Colour of the back dusky red, brighter on the 
head and lips; hindmost gill-covers red; a slight gold-coloured 
line from the eye backward; pale green on the belly; near 
the upper margin of the tail, between it and the termination 
of the dorsal fin a broad and conspicuous dark mark. Fins 
inclined to red, the three first rays of the dorsal bluish black. 
Eye crimson. 
As in the other species of this family, there is in this a 
disposition to vary in the distribution and intensity of the 
colours, and even in the form, the elevation of the top of the 
head being much more considerable in some than in others. 
In rare instances the broad spot near the tail is wanting. 
Again there are in some examples longitudinal bands of 
colour on the dorsal fin, and curved lines of bluish purple on 
the cheek. 
