Parker's silurus. 189 



firmness, which sends off two posterior appendices 

 towards the upper part of the branchial apertures ; 

 the middle of its posterior margin is notched to re- 

 ceive the apex of a very strong heart-shaped bone, 

 the lobes of which reach the base of the dorsal fin. 

 This shield or plate is rough, with bony granulations, 

 of a larger size than those of the armour of the head, 

 and is obtrusely carinated towards its posterior 

 part. 



" The head is very broad ; the mouth is wide, 

 terminal, and furnished with numerous minute teeth, 

 which are rather intended for holding fast, than 

 biting the prey of the animal. These teeth are 

 thickly placed on the edges of the mouth, in such 

 a manner as to resemble the hairs of a very stiff 

 brush. They are arranged in two groups about half 

 an inch wide, on each jaw, reaching along the whole 

 aperture of the mouth, and are divided in front by 

 a single furrow. Two convex, oblong bones, of con- 

 siderable size, and furnished with similar teeth, form 

 the osseous palate of the fish. The eyes are small, 

 placed rather above the line of the mouth, and more 

 than an inch and a half from its angles. There are 

 six tentacula or cirrhi on the lips. The longest pair 

 are on the upper jaw, very near the angles of the 

 mouth, and measure full eight inches in length. The 

 next pair are more than an inch below the lower 

 jaw-bone, and measure four inches and a half. The 

 shorter pair are placed near the middle of the lower 

 jaw, and measure two inches and a half. 



" The first ray of pectoral and first dorsal fins con- 



