COMPARATIVE STUDY OF SCOMBROID FISHES. 
335 
Scomber japonitus 
Cybium niphonium 
Sarda orientalis 
Gÿmnosctrda nuda 
Vhunnus orientalis 
Katsuwonus pelamis 
portion in length. The 
posterior stjliform process 
i3 rather short. In Gymno- 
sarda the external wing 
of the anterior external 
portion is turned obliquely 
towards the external, ven¬ 
tral side, and is not thicken¬ 
ed nor folded at the 
external margin. In the 
Thunnidae the pelvic girdle 
is very strongly developed. 
The anterior external por¬ 
tion is broad, rather thick, 
and the dorsal exterior 
margin is also thick and 
folded. In this family the 
external and ventral wings 
of the anterior external 
portion are nearly in one 
plane, and the internal 
wing is united to the 
middle of the plane, formed 
by the other two wings. 
The external wing is folded 
at the external margin. The anterior internal portion is a little longer than the 
ventral wing of the anterior external portion. In the Katsuwonidae the pelvic 
girdle is more specialized. The anterior external portion is thin, and fan-shaped, 
with a thick external margin. The anterior internal portion is more or less longer 
than the outer, especially in Euthynnus and Avxis. The styliform process is very 
long and laterally compressed. Fin-rays are directly articulated to the thick 
portion where the three different portions of the arch meet. 
Auxis maru 
Fig. I. Left external view of the pelvic girdle. 
