88 



ACCOUNT OF FIVE RARE SPECIES 



Length, twenty inches and a half, viz. ten to 

 the vent, and ten and a half to the end of the tail : 

 the snout is similar to that of acus ; its length to 

 the eye three quarters of an inch ; from thence to 

 the end of the gills including the eye, one inch i 

 the form of the body is rather compressed, and 

 angular, with an acute dorsal, and abdominal 

 ridge, which, together with three slight angles on 

 each side, gives it an octangular appearance : it is 

 of equal size from the gills to the vent, which 

 part contains about thirty plates ; from the vent 

 to the extremity of the tail it is almost round, and 

 extremely taper, containing about sixty-six plates : 

 immediately behind the vent, the body of this 

 specimen suddenly decreases to one-third less iii 

 diameter ; but this may be a sexual distinction. 



The dorsal fin consists of forty rays, commen- 

 cing considerably before the vent, and terminating 

 rather behind it, so that three-fourths of the fin is 

 before the ventral aperture. It has neither pec- 

 toral nor anal fin. The end of the tail is extreme- 

 ly small, and compressed into a spurious fin, the 

 rays of which are enveloped in the common skin, 

 and are scarcely definable by a lens, and not vi- 

 sible to the naked eye. The colour is yellowish, 

 with transverse pale lines, with dark margins, one 

 in each joint, and another down the middle of 

 each plate, giving it the appearance of possessing 

 double the number of joints it really has : these 

 markings, however, cease just beyond the vent. 



