of the Fishery Board for Scotland. 



137 



Colours and Scales. — The three species have silvery snouts, cheeks, and 

 shoulders. 



Minutus has large silvery scales that are very easily rubbed off. The 

 exposed part of the scale is covered with dark dots on a ground of silver. 

 The overlapped part of the scale is colourless. The scales of the dorsum 

 above the lateral line have a golden-yellow ground dotted with black. 

 The golden-yellow colour is also seen on the silvery scales on the side. 



The scales of luscus are smaller than those of minutus-, they also are 

 very deciduous. On the scale from the side of luscus there is a broad 

 edging of black dots. Beneath the scales the skin is thin and somewhat 

 iridescent. When wet the skin of luscus has a slight golden sheen, but 

 when dried the black-dotted scales give it a dirty black appearance. In 

 large specimens preserved in formaline the appearance is silvery, but 

 the skin has generally a blackish aspect. 



When preserved, minutus remains of a brownish-yellow colour, that is 

 when the silvery scales are rubbed off, as usually happens. Where they 

 remain attached the skin becomes of a dark appearance. The skin is of a 

 rougher texture than that of luscus. It is slightly pinkish on the dorsum. 



In both species the belly is silvery. Esmarkii also is silvery on the 

 sides. 



The Axillary Mark. — In luscus the axillary mark is a large blue-black 

 patch covering the sides of the axilla, and extending out on the clavicle 

 and over the base of the pectoral fin. In minutus it is a small dark area 

 on the axilla and the base of the first pectoral fin-ray. It does not 

 extend on to the clavicle much. In esmarkii there is a very similar 

 axillary mark to minutus : it is a collection of small black dots which 

 spread over the base of the pectoral fin. 



The Peritoneum in esmarkii is black, and in preserved specimens the 

 black layer shines through the thin abdominal wall. 



The Fins. — The anal fins of luscus are blue-black; those of minutus 

 yellow and black spotted. The first anal of minutus is sometimes very 

 dark. 



Most of the unpaired fins of esmarkii have a black border. Thus the 

 anterior border of the first dorsal is black, while the superior and hind 

 borders of the second and third dorsal fins are likewise black. The black 

 parts of the second anal and caudal fins are the hind border and the hind 

 half of the fin respectively. There are black spots along the bases of the 

 fins, and also on the anterior border of the first anal. The anal fins of 

 preserved specimens are without pigment, except on the anterior part of 

 both fins, where a small area is covered with small dots. This character 

 is more prominent in the larger specimens. The caudal fin is more or 

 less all black. 



The second and third dorsals are separate in minutus and in esmarkii, 

 and are usually separate in luscus. In one specimen of luscus, however, a 

 male measuring 16 "8cm. in length, the second and third dorsals were united. 



The first and second anals are separate in minutus and esmarkii, but 

 are united in luscus. There is a thick integument on the unpaired fins in 

 luscus and minutus. In the former the first anal is a thick flabby fin, the 

 integument being soft and loose. This fin is often inflated with a gas, 

 which can be pressed out at the edge. 



There is a characteristic difference between luscus and minutus in the 

 shape of the third dorsal and second anal fins, as will be seen by reference 

 to Plate VIII. The hind edges of these fins in luscus are cut straight 

 across, at right angles to the longitudinal axis of the fish. In minutus 

 the hind edges slope away posteriorly. In esmarkii the slope is more 

 pronounced and longer than in minutus (pi. ix.). 



