302 
KAMAK1CHI KISHINOUYE : 
of the body (fig. 35). The head is somewhat triangularly pyramidal, as its 
upper surface is more or less flat and the lateral sides oblique, meeting at the 
ventral median line. This characteristic form is very well developed in the 
Plecostei, while it is rather a little modified in the Cybiidæ, as the head is 
more compressed laterally than in other families, and its top is more or less 
vaulted. 
In the Scombriclæ the snout is moderately long, ca. 1/3 the length of 
head, and the posterior nostrils are slit-like. In the Cybiidæ the snout is 
much elongated, being nearly equal in length with the part behind the eye. 
The anterior and posterior nostrils are nearer to each other, than in the 
Scombridæ and Plecostei, and the posterior nostrils are more or less elliptical 
and a little larger than the anterior. In the Plecostei the snout is ca. 1/3 the 
length of the head, but it seems rather short, as the head is broad. In the 
genus Auxis the snout is very short, being only ca. 1/4 the length of the 
head. The Japanese name for the fishes of that genus is “ medika,” which 
means that the eye is near the snont. The antrior nostrils are quite small, 
and the posterior nostrils are mere slits. 
The mouth is terminal, not protractile. In the Scombridæ it is rather 
wide, the hind end of the upper jaw reaching or passing beyond the vertical 
from the middle of the eye ; and the margin of the upper jaw is mostly 
formed by the preorbital. The supplementary bone to the maxillary is very 
narrow and small in this family. In the Cybiidæ the mouth is very wide, the 
posterior end of the upper jaw generally reaching beyond the posterior margin 
of the eye. But in Acantliocybium, Grammatorcynus, and Gymnosarda the 
maxillary scarcely reach the vertical from the center of the eye. In Acantliocybium 
the preorbital forms the posterior part of the upper jaw. The supplementary 
bone to | the maxillary has its posterior end rounded. In the Plecostei the 
mouth is comparatively small, the posterior end of the upper jaw not reaching 
the vertical from the middle of the eye. The supplementary bone to the 
maxillary has a broad straight side at the posterior end. An obliquely 
downward grove in the skin from the gape of the mouth is deep and 
conspicuous. 
In the so-called scombroid fishes the teeth in the jaws are arranged in 
one row only. They are a little more numerous in the upper than in the 
