'398 'I'lIK FliE.SII-WATEU FISIIKS OF EL'UOl'K. 



L'xtentj between the parietal and scjuaniosal. Poi-es are developed between the 

 squamosal and frontal shields, and oceur in rows between the small shields on 

 the snout. On the under side of the snout (Fig. 188) the median ridg-e is small 

 and smooth, and reaches back only to the barbels, which are nearer to the 

 extremity of the snout than to the mouth. The outer barbels are the 

 lono'er. The mouth-aperture is wide, bounded anteriorly by a small u])])er 

 lip, which is entire, and is produced only for a short distance beyond the 

 angles of the mouth, so as to leave the entire centre of the lower jaw free. 

 The eyes are of moderate size, equal, and ovate. The breadth of the frontal 

 interspace is six times the orbital diameter. The lower and larger narines are 

 smaller than the diameter of the eye. The shields on the body are strong, but 

 distant from each other. The number of dorsal shields is about ten to eleven, 

 their bases are sometimes round, sometimes heart-shaped ; the keel is smooth, 

 strongly elevated, and forms a curved point or hook, which extends back- 

 ward. The first dorsal shield is not firmly attached to the supra-oceipital 

 shield ; the third shield is the highest. Those which succeed the third 

 are broader than long, and become smaller as they extend down the back. 

 They are regularly rayed. The lateral shields vary in number from thirty 

 to thirty-three ; they are lozenge-shaped, finely rayed and keeled, but towards 

 the tail the keel is prolonged into a hook. The ventral shields also each have 

 a keel ending in a hook; they are more ovate, and seven to nine in number. 

 One or two similar shields lie between the vent and anal fin ; and there are 

 often a few smaller bony scales behind the dorsal fin, on both sides of the 

 body. The skin is smooth and shining between the rows of shields, but 

 there are star-shaped bony scales thickly scattered over the surface. They 

 vary in size and shape. Some of the larger are elevated into a spine, and 

 they form an irregular row between the dorsal and lateral shields. There 

 are small pores on the under side of the snout. The skin is smooth about the 

 mouth, eyes, nares, gill-aperture, and the region of the pectoral, ventral, and 

 anal fins. All the fins are pointed. The pectoral fin is longer than the 

 diameter of the body. One unjointed soft ray succeeds its bony ray. The 

 dorsal fin is very strongly notched out posteriorly. The upper lobe of the 

 caudal fin is not conspicuously long. 



The colour is blackish-grey above, and yellowish-white below ; the shiekls 

 are dirty white. 



In the young the head is relatively large, and is about one-cjuarter of 

 the entire length ; and then the barbels are midway between the mouth and 

 the extremity of the snout. The upper lij) is notched. The lower lobe of 

 the caudal fin is less developed. The length both of the snout and of tlie 

 hooks on the shields varies with age, as in all other species of the genus. 



