of the Fishery Board for Scotland. 



133 



Otoliths. — Generally, the otolith of minutus was heavier, more massive 

 than that of luscus, in fish of the same length. The bossing or marking 

 on the concave surface of the earstone is more distinct in luscus: it tends 

 to become smoothed down in minutus. Two minutus of one length 

 had very different otoliths; in one they were much more massive than 

 in the other fish. 



The otolith of esmarkii shows a tendency to transverse ridging in place 

 of, or in addition to, bossing on the concave surface. 



The clavicle, SfC — Slight differences are to be seen in the clavicle, post 

 clavicle, and premaxilla between minutus and luscus. Thus, in the 

 clavicle the ridge dividing the outer surface of the bone is broader and 

 more prominent in luscus than in minufus. The post clavicle of minutus 

 has a curved expanded superior end ; in luscus the head of the bone is 

 expanded and bent a little off the straight. 



In the premaxilla the only noticeable difference was in the rather 

 longer and narrower shape of the plate expansion on the distal part of the 

 bone in minutus. 



Teeth. 



The teeth are small in luscus and minutus and minute in esmarkii. 



A Discussion of the Species. 

 Gadus luscus and G. minutus. 



Only a very brief notice of the literature is necessary. Yarrell gives 

 characteristic figures of luscus and minutus. The specific characters are 

 treated only briefly. He says with regard to luscus that it has the 

 power of inflating a membrane which covers its eyes, and for that reason 

 it is called Pout, Bib, Blens, Blinds. Tha aims is in a line under the 

 origin of the pectoral fin. The end of the rays of the tail are nearly 

 square. It has a dark spot at the origin of the pectoral fin. The Bib is 

 the deepest gadid. The fin-formula given by Yarrell is — 1 D, 11 ; 2D, 

 20 ; 3 D, 16 ; 1 A, 33 ; 2 A, 19 « P, 18 ; V, 6. Vertebrae, 48. 



G. minutus has, according to this author, the following fin-formula : — 

 1 D, 12 ; 2D, 19 ; 3 D, 17 ; 1 A, 25 ; 2 A, 17 ; P, 14 ; V, 6. 



At different times the identity of the two species, G. minutus and G. 

 luscus has been maintained. This is the view which Smitt maintains in 

 the last edition of the Scandinavian Fishes," although plates showing 

 perfectly characteristic luscus and minutus are included in the work. 

 According to this author, Steindacher had asserted that the depth of the 

 fish is merely a character of age, and he referred to the same category the 

 character derived from the union of the anals in luscus and their separa- 

 tion in minutus. The comparative depth of the two species is certainly 

 not a character that can be relied upon. But the deficiency in the second 

 character mentioned I have not been able to find in the adult. Schmidt 

 found this a very reliable character in the very young stages. Further, 

 Smitt remarks that "the size of the eyes has been long since ascertained 

 to undergo a relative diminution with increasing age." The relative size 

 of the eyes in luscus and minutus is not of much importance. 



Smitt has compared 5 minutus and 3 luscus with respect to a large 

 number of characters. In a considerable proportion of these very close 

 agreement is found between the two species. That is to be expected, 

 since luscus and minutus resemble one another closely ; in fact they form 

 a small group of two fishes very distinct from the other Gadids. The 

 following are the characters which Smitt selected : — Length of the head ; 

 distance of the beginning of each of the three dorsal fins from the tip of 



