COMPARATIVE STUDY OF SCOMBROID FLSHES. 427 



Lateral line runs p;ir;illel to the doi-s;il outliuo of the body, nearly to the 

 twelfth spine of tlio (iret dorsal. Below the spino the Uno is bent downward. 

 Behind tlie vertical from the first dorail finlet, a few undulations in the line. 

 Scales of the lateral line are also concealed under th« skin, and on both 

 sides of the pored sodes we find two or three i*ows of minute scales. The 

 lateral keel of the caudal portion is also covered with minute, clonfi;ated 

 scales. The third spine of the first dorsal is longest and thickest, though 

 RÜPPEL reports that in his six-ciniens the second spine is the longest. Air- 

 bladder ku'ge and think-walled, though Rüppel denies its presence. Pyloric 

 coeca form a conspicuous mass in the abdominal cavity as in other forms of 

 the CybiidLie, so that it is strange that they escaped the eyes of Rüppel, but 

 the fact tliat the mass of the coeca is enormously developed deceived the 

 naturalist, probably the mass was taken as a pxrt of the liver or other organs, 

 as KIIjUNZINGER (49) remarked in his work. 



Skeleton fir.n and strong. Tlie number of vertebrae is very small, compared 

 to that of the species of Cyhium. Skull flat and broad. Anterior half of the 

 frontals is provided with many oblique ridges, and covered directly with the 

 skin. Posterior margin of the preopercle is a Uttle undulating. Dorsal 

 anterior margin of the opercle is slightly concave. Inner Umb of the 

 suboporcle is Iiu-ge. First vertebra is very thin and its neural process is free 

 from the centi'um. Auturior preeaudal vertebrae want the parapophyses, and 

 the lateral keel of the caudal peduncle is narrower than the diameter of the 

 centrum. The last haemal process is coalesced to the fan-shaped hypural 

 bone. Cross-section of vertebrae is not ex;tctly cruciate in most of them, but 

 more or less sex-radiate. Haemal arch is formed from the eleventh vertebra, 

 and haemal spines of some length are found in preeaudal vertebrae. Inter- 

 muscular bones are very numerous, being found to the 29th vertebra. 



Colour is said to be dark bluish to violaceous at the back, and greyish 

 white at the belly. Top of the head and the anterior end of the lower jaw 

 are greyish. Fins are black or greyish, leaving the tip of the second dorsal 

 and anal colourless. 



It is told tliat the fish attains the big size of about 240 cm with a weight 

 of 80 kg ; but fishes now commonly caught at the Ogasawara Islands are 100- 

 150 cm in length, and 20-30 kg in weight. 



