216 RIBAND-SHAPED. 



of the most anterior spot being at the commencement of the 

 second fourth part of the whole length of the fish, the pos- 

 terior being situated about half way, or near the middle. 

 Both spots are nearer each other in the Tr. leiopterus than in 

 the present species. The total length of the specimen repre- 

 sented, measured from the point of the nose to the end of the 

 dorsal column, is forty-three inches six lines ; with the upper 

 jaw protruded, the whole length is forty-four inches seven 

 lines. The greatest height of the body in the present spe- 

 cimen, twenty inches from the angle of the mouth, or four 

 inches in advance of the anus, is contained five times and a 

 half in the length, while the height at the nuchal region, 

 about six inches from the end of the nose, is contained nearly 

 seven times in the total length. The height at a distance of 

 thirty-six inches is but a little more than one-eleventh of the 

 total length, and at the distance of forty inches is little more 

 than one-thirtieth. 



The greatest diameter is near the part where the gill-cover 

 is attached to the head, and is contained four times in the 

 height of that region, or five times in the greatest height, the 

 diameter of which is scarcely one-tenth. The diameter de- 

 creases towards the narrow part of the tail. The greatest 

 diameter of the body is in the region of the lateral line, and 

 decreases towards the dorsal and ventral profile, particularly 

 towards the former, where it becomes sharp like the edge of 

 a knife, by which the spinal processes and the intervening 

 bones of the dorsal rays become apparent on the surface of 

 the thin external covering. 



The head from the end of the nose to the posterior margin 

 of the gill-cover is contained seven times and a quarter in the 

 total length ; the length of the head is therefore nearly equal 

 to the height of the fish at the nuchal region. The outline 

 of the lower jaw forms an ascending arch, which at the angle 

 of the mouth meets the straight and slightly declining profile 



