found in the subfamily Tetrapturinae and the latter is found 

 in the subfamily Marlinaeo The form of the vertebrae in the 

 Xiphiidae differs greatly from that in the Istiophoridae. In 

 the middle caudal vertebrae the centrum is somewhat elongated^^ 

 but in the majority of them there is little difference between 

 the length and height„ Neither the neural spines ncr the hemal 

 spines are thin flat plates^ but rather flattened, fairly broad 

 spines in form„ The neural processes are not produced anteriorly, 

 but are directed obliquely upward to support the neural spine 

 of the preceding vertebra,. The hemal process is much less con-- 

 spicuous than the neural processo The transverse processes are 

 well developed, and the ribs are articulated to them. The ver- 

 tebral count is 16 / 10 e 26, two more than in the Istiophoridaee 



The anterior part of the posttemporal bonej which is 

 bifurcated in the Thunnidae, has three prongs in the Istiophori- 

 daee Its posterior edge is generally rounded^, but its form is 

 not the sam.e in all specieso There is also an additional tri- 

 angular projection which points obliquely to the rearo The 

 supraclavicle is generally spatulatej, with its upper end irregular 

 in shape and tapering gradually to a pointy its lower end rounded^, 

 and its middle portion somewhat constrictedo The anterior margin 

 of the clavicle in Marlina marlina and Kajikia mitsukurii is 

 slightly concave above and slightly convex belowp but on the 

 whole roughly straight in outlineo In the other fishes of the 

 Istiophoridae the middle portion has a large concavity. The 

 surface for the articulation of the hypercoracoid with the acti- 

 notis present differences as between species ^ being broad and 

 horizontal and somewhat twisted anteroposteriorly in the white 

 marlin^, and narrow, obliquely slanted, and not tmsted in the 

 other specieBo Differences between species can also be detected 

 in the breadth and form of the shoulder girdle as a wholeo The 

 differences between the two families are conspicuousc 



The pelvic girdle is well developed in the Istiophoridae 

 and presents a somewhat palmate form. In the white marlin the 

 left and right sides are joined together and are hard to separate^, 

 but in the other species the space between the two sides is 

 broad and they are easily separated, The ventral fins are com- 

 posed of three raySj, the first of which is a very short spine^ 

 while the other two are long„ all of them being closely joined 

 to each other^ In the Xiphiidae both the pelvic girdle and the 

 ventral fins are completely lackingo 



A number of the interspinuous bones anterior to the first 

 dorsal and the first anal fins are joined to each other, but in 

 the more posterior ones the space between adjacent bones gradually 

 increaseSo Marked differences between species can be seen in 

 the anteriormost interspinous bones of the first dorsalo The 

 interspinous bones of the second dorsal and the second anal are 

 somewhat similar j, being firmly joined to each other^ and the 



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