of the Fishery Board for Scotland 



129 



There are two characters which have not so far been mentioned. One 

 of these is the shape of the skull (figs. 15 and 19 and page 1 22), which is 

 very distinct from that of callarias, and the second is the presence of 

 black pigment on the external wall of the ovary (fig. 76, ov.), and also 

 inside that organ. I have not, so far, noticed black pigment in the 

 ovary of any other Gadid. This ovary of ogac contained small yolked 

 eggs measuring *3 mm. in diameter, large yolked eggs *65 mm, in 

 diameter, and clear eggs '05-2 mm. in diameter. 



As Vanhoffen pointed out, ogac comes very near callarias in the number 

 of fin-rays in the unpaired fins, but a similar relationship exists between 

 other Gadids, e.g., virens and pollachius, luscus and minutus. The 

 following are certain points which were prominent in this fish (figs. 21 

 and 1 3a) : — The barbel is long, stout on one example. The lateral line has 

 a bend that is not very pronounced ; it meets the lateral axis about the 

 first half of the second dorsal. The skin is of a uniform dark brown all 

 over. The peritoneum is very dark. There is an external anal tube (fig. 

 13a) in one example. The ureter opens to the exterior by a small median 

 aperture close behind the wide genital opening. The tail fin is slightly 

 concave on its hind edge. The abdominal cavity extends back to about 

 the middle of the first anal fin (fig. 7 6). The piebald colour of the ovary 

 is noteworthy (fig. 76). The inside of the mouth is brown-coloured. 



The specimen belonging to the Copenhagen Museum was much smaller. 

 It measured 33*5 cm. in length. It is shown reduced in Plate VII. The 

 hind margin of the tail is distinctly concave, with the rami of the tail 

 rounded. The forehead is flattish. The barbel is long, and not very 

 stout. There is no distinct anal tube, although there is a raised border 

 round the anas, and there is a fairly long genital tube projecting. 

 The lower jaw is very little short of the upper when the mouth is 

 closed. 



The fish is of a laminarian colour all over ; the abdomen is of a lighter 

 shade of the same colour. The scales are brownish-tinted, transparent, 

 except at the exposed part, where there is a patch of dark brown pigment. 

 The rings of growth on the scales are well marked. The lateral line is 

 continuous, except from the middle of the third dorsal backwards, where 

 the scutes are separate. Both ogac and callarias have the sensory pro- 

 cesses, possessed by other Gadids, on the inside of both lips. The pits 

 on the skin of the mandible are common to other species of Gadus in 

 addition to ogac and callarias. No difference was made out in the teeth 

 between the two species. 



Gadus navaga is a small species. Its specific characters are given by 

 Giinther as follows : — 



Barbel small ; shorter than the eye, the diameter of which is somewhat 

 less than the width of the inter-orbital space and one-half of the length 

 of the snout. The snout is sub-conical, obtuse, with the upper jaw the 

 longer. The height of the body is less than the length of the head, 

 which is one-fourth of the total (without caudal). The vent is situated 

 vertically below the origin of the second dorsal. Tail very slender, fins 

 separated by interspaces from one another. Caudal fin truncated. 

 Colour, brownish with reticulated dark lines on the back. 



Size — Seven to nine inches long — White Sea. 



Kolreuter says that the colour is brown over the dorsum without spots. 

 The swim-bladder has two horns. 



The specimen kindly lent by Dr, Jungersen was obtained in Greenland 

 (fig. 84). In general colouring it was not unlike a small cod that had 

 been preserved in alcohol. It has a little stumpy barbel with a fine tip, 

 nearly resembling that of aBglefinus. The tail fin was damaged, one 



