234 NORTHERN ZOOLOGY. 



runs backwards. The intermaxillaries and labials form nearly equal portions of the upper 

 jaw : the former are almost immoveable, but the ends of the latter are thrust forward a little 

 as the mouth opens. Lower jaw strong. 



Teeth conical, in a single row on the intermaxillaries and labials, those on the former 

 being considerably the largest : there are two rows having their points inclined backwards on 

 the lower jaw, with an intervening narrow bony surface covered with minute teeth. The 

 vomer projects from the roof of the mouth and is armed like the lower jaw. The palate-bones 

 are rough with minute teeth. The tongue is furnished on its margins with hooked teeth 

 which are the largest of all, and its centre is occupied by a crowd of small curved ones (" dents 

 en carde"). Club-shaped cartilaginous rakers, rough with teeth, stand in double rows on 

 the anterior edges of the branchial arches ; and at the union of the arches, both above and 

 below, there are thin plates covered with small teeth. The thick gill-membranes contain nine 

 small cylindrical rays : the left membrane overlaps the right one at their insertion into the 

 isthmus. 



Fins.— Br. 9; P. 12; V. 7 ; A. 34; D. 11 ; C. 



The first ray of the pectorals is considerably stronger than the others. The ventrals, situated 

 halfway between the pectorals and anus, are small and contain seven rays, which support a 

 delicate membrane. The anal, occupying the whole of the upper slope behind the anus, con- 

 tains thirty-four rays, which become successively shorter as they are more posterior : the edge 

 of the fin is slightly waved. The small dorsal, opposed to the anal, contains eleven rays. 

 The caudal is crescentic, its lower lobe being rather the largest. 



Scales irregularly orbicular and large, being about half an inch in diameter ; when in situ 

 they have a bluish-grey colour at the base with bright silvery tips. The irides and sides of 

 the head are tinged with honey-yellow. The lateral line is straight till it passes the dorsal 

 fin, when it is slightly deflected. 



Intestines. — The oesophagus is distinguished by its more delicate and whiter internal folds 

 from the stomach, which is a long tube that makes a curve at its fundus, and has its lining 

 disposed in nine or ten longitudinal folds of a reddish colour : its pyloric orifice is much con- 

 tracted. Immediately below the pylorus the intestinal canal dilates considerably, after which 

 it forms a tube of equal diameter throughout, and nine inches long, without any distinct 

 rectum : its lining is villous and destitute of valvules conniventes. An obtuse ccecum, three- 

 quarters of an inch long, opens into one side of the dilated intestine next the pylorus, and the 

 gall-duct into the other side. The thin faeces of the lower intestine have a honey-yellow 

 colour. The alimentary canal makes one convolution in its course from the oesophagus to the 

 anus. The oblong liver lies mostly on the right side, there being merely a small lobe on the 

 left : it has a reddish-orange colour. There are two small spleens. The air-bladder is 

 capacious and communicates with the oesophagus. The kidneys are bluish-grey, thickly 

 studded with dark brown specks. The lining of the abdomen is of a pearly hue, and the roe 

 pure white. 



