222 DISCOBOLI. 



this coast, but in no other way than on the bodies 

 of sharks or the bottoms of vessels. The one un- 

 der consideration usually measures from four to 

 twelve inches, and is of a leaden color ; the body 

 is long and slender, covered by minute scales, and 

 on the back is one dorsal fin without spines. On 

 the top of the head is an oval spot which looks, at 

 first view, as though a slice of the cranium had 

 been cut off nearly on a level with the eyes. This 

 oval place is termed a disk, constituted of two 

 rows of transverse plates like the bars of a gridiron. 

 Perhaps to compare the bars with a Venetian 

 window blind, will convey abetter idea of the ap- 

 pearance than anything else. Each plate stands at 



THE SUCKING FISH. 



about the same angle as the slats of the blind, and 

 there is a space between every two of them. If the 

 edges were turned towards the snout, they would 

 be thrown up, and thus retard the motion of the 

 fish ; but by being directed backward, the greater 

 the velocity the closer do the edges of the plates 

 fold down over the spaces. 



There are eighteen in this species, nine in each 



