304 
KAMAKICHI KISHIKOÜYE: 
The position of this oblique portion is either under the first dorsal or under 
the second. In fishes of this family the lateral line often sends out many 
branches on both sides (figs. 33, 32, 35), and these branches are vertical in 
Acanthocylium, but oblique in Cybium. The perforated scales are larger, 
thicker, and greatly modified in their form, and they may also distinctly be 
seen on the lateral keel of the caudal peduncle, at the trenchant edge. 
The lateral line of Cybium koreanum (fig. 35), C. guttatum (fig. 61), Sarda 
orientnlis (fig. 33), and Gyrnnosarda nuda (fig. 37), differ more or less from 
the typical form. In Grammatorcynus two lateral lines are found on each 
side of the body (fig. 62). The upper lateral line seems to correspond to 
the normal lateral line, running parallel to the dorsal median line of the 
body. The lower lateral line joins the upper with a right angle behind the 
pectoral, and running down backward approaches the ventral median line, a 
little behind the ventrals. Thence the line runs parallel to the ventral 
median line, and meats the upper lateral line, a little anterior to the lateral 
keel. 
In the Plecostei perforated scales are very little modified, and the 
undulation of the lateral line is not much pronounced ; but it has a more or 
less characteristic feature in different families. It is worthy of note that the 
lateral line of the Thunuidæ always takes a peculiar course, aloove the pectoral 
(figs. 43, 45-48). In this region the course of the lateral line is rather 
difficult to trace, as the pores are indistinct, few iu number, and much 
separated from each other. The lateral line of Thunnus. orientalis is typical. 
The lateral line of the Kcdsuwonidœ has only a slight rise above the pectoral, 
and has small undulations at the caudal portion. Klunzinger (49) wrote in 
the diagnosis of Thunnus thunnina as follows :— 
“ Die Seitenlinie bildet zuweilen eine Knickung nach oben über der 
Mitte der Brustflosse ; dann senkt sie sich, etwas unregelmässig wellig laufend, 
bis zur Mittellinie.” 
This description is well adapted to the lateral line of tunnies, but not 
proper for that of bonitos. Indeed the author confounded immature tun oies 
with bonitos, identifying Orcynus schlegeli of Steindachner (immature form 
of our common tunny) with Thynnus thunnina. 
