426 
KAMAKICHI KISHINOUYE: 
vertebrae is 22 + 22. The dark stripes in the back are fewer, and more 
oblique in S. chilensis, and much wider apart than in S. orientcdis. 
Genus Gymnosarda Gill. 
Gymnosarda, Gill, 1862. 
Body long, fusiform with a large head. Mouth large, but the maxillary 
does not reach beyond the orbit. Eyes large. Scales in the corselet elongated, 
and concealed under the skin. Outside of the corselet and the base of the 
fins the skin is entirely naked. Lateral line undulating. Teeth in jaws 
large, curved, and nearly conical. Villous teeth on the tongue and palatines, 
but the vomer is toothless. Caudal portion very slender with a well developed 
keel on each side. 
First vertebra is very short. Cross-section of caudal vertebrae is more or 
less cruciate, but tire lower end of the perpendicular limb is always bipartite. 
Anterior precaudal vertebrae with three ventral grooves. In external ap¬ 
pearance fishes of this genus are closely related to tunnies. 
Pelagic fish of voracious habit, and of somewhat large size in the 
littoral waters of the tropical region, chiefly Indo-Pacific ; but a species is 
recorded from European waters,—the Mediterranean and the North Sea. In spite 
of great differences in external characters, as well as in the internal anatomy, 
many authors confounded this genus with the genera Katsuwonus and Euthyn- 
nus of the Katsuwonidae. 
Gymnosarda nuda (Günther). 
Isomaguro (Ogasawara Is.), tokakin (Byukyu Is.). 
Thynnus ( Pelnmys ) unicolor, K'ippel, N. W. Fisch., 40, Taf. 12, Fig. 1, 1838. 
Pelamys nuda, Günther, Cat. Brit. Mus. II, 368, 1830 ; Klunzinger, Fisch, d. Both. Meer., 
110, 1884. 
Gymnosarda nuda, Kishinouye, Sui. Gak. Ho, I, 13, PI. 1, Fig, 8, 1915. 
D. 14, 13, 7. A. 12, 6. Gill-rakers 2 + 10. Vert. 19 + 19. 
Body fusiform, entirely naked outside of the small corselet. Head com¬ 
paratively large and the caudal peduncle very slender. As the scales of the 
corselet are concealed under the skin, small wrinkles are found around the pecto¬ 
rals, and several longitudinal furrows on both sides of the dorsals. Lower jaw 
broad. Teeth in the upper jaw are 18-23, and in the lower jaw 10-16. 
