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KAMAKICHI KISHINOUYE : 
bands, while the fish belonging to the genus Sarcla have many longitudinal 
bands on the back (fig. 33). In a small immature specimen of Sarda orientalis, 
obtained on the east coast of Aomori-ken, I found 13 transverse bands, and in 
these bands, five to seven, oblique longitudinal bands, were found. Fishes 
belonging to the genus Gymnosctrda have no markings at all (fig. 37). In 
the Cybiidæ dots and bands are generally few in number in immature forms, 
and the markings increase in number by intercalation as the fish grows 
larger. Cybiurn niphonium under 10 cm in length, and Gybium Jcoreanum 
under ca 20 cm lack markings entirely. 
In adult tunnies we find no markings, except many silvery lines and dots 
in the belly of certain species (fig. 45, 48). These silvery dots and lines are 
not found in the other scombroid fishes. Adult bonitos have dark bands 
generally transverse in the back ; but they are not conspicuous in the genu 
Kcdsuwonus (fig. 53), as the bands are very broad and quite near each other. 
Longitudinal bands on the belly of Katsuwonus and dark spots in the thoracic 
part of Euthynnus (fig. 54) are characteristic to the respective genus. Generally 
small immature forms of plecostean fishes are transversely banded and they 
extend from the dorsal median line to the ventral median line. These bands are 
broad an I they approach each other very closely, in the Thunnidæ ; but in 
the Katsuwonidæ they are rather narrow, being more narrow than the interval 
between them, and are short, not reaching the ventral median fine. Small 
immature forms of Tkunnus orientalis (fig. 43) and Neothunnus macrop'erus 
have many dark transverse bands, which gradually disappear from the dorsal 
side, when the fish is about half a year old ; but the ventral part of these 
bands remains all through life (fig. 45). As the fish grows larger, these 
bands in the belly are subdivided by a series of dots. These boundary lines 
and series of dots gradually incline obliquely backwards, towards the ventral 
median line (fig. 45). In Parcithunnus mebcichi of ca. 90 cm in length I found 
ventral markings, but in larger specimens they disappear entirely. In Thunnus 
rermo and Neothunnus rarus (fig. 48) irregular longitudinal bands of greyish 
colour are found in the belly, and they anastomose with each other, leaving 
silvery meshes. In the former species the marking disappears in larger 
specimens, but in the latter, it remains lifelong. Pigments and silvery 
ingredients of bonitos are found at the surface of the skin. Therefore when 
