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KAMAKICHI KISHINOUYE: 
the blue-finned tuna from San Pedro, Cal., I found the axial margin of the 
cutaneous vein partly covered by the abaxial margin of the accompanying 
artery. In Euthynnus (all known species inclusive), however, the cutaneous 
artery lies on the abaxial side of the accompanying vein, and the axial margin 
of the cutaneous artery is partly covered by the abaxial margin of the 
accompanying vein (fig. 26). The distribution of smaller canals on the wall 
of the cutaneous arteries is variable in different species, and so far as I have 
examined, there are no two Japanese species of tunnies which have the arterioles 
distributed in the same way (figs. 20-24). 
In Thunnus germo arterioles are distributed on the external axial side of 
the artery in two or more rows, and they rim axially. In Thunnus orientalis 
arterioles are found on the internal side in one row, in Parcdhunnus mebachi 
in two rows, internal and external, in Neothunnus racier opter us in one row or 
two indistinctly aiternate rows on the side near the lateral median line of the 
body, and in Neothunnus rarus in one or two alternate rows at the middle of 
the abaxial side. In the Katsuwonidae, the cutaneous artery of the epaxial 
side would be homologous to both the epaxial and hypaxial branches of the 
cutaneous artery of the Thunnidae. The hypaxial cutaneous artery of the 
Katsuwonidae is remarkably short and slender, it generally originates in front 
of the epaxial artery, and takes a forward direction, and after passing through 
the kidney turns backward, it is situated in a more ventral position than the 
hypaxial branch of the cutaneous artery of the Thimnidae. In Katsuwonus the 
epaxial and hypaxial arteries are nearly equal and originate from a common 
lateral branch of the dorsal aorta, in the hind part of the segment of the sixth 
vertebra, just behind the pharyngeal muscle. The common lateral branch of 
the dorsal aorta is very short, horizontal. It is divided in the kidney into 
two canals or rather it is united to a gently curved canal, two limbs of 
which are turned backward. The epaxial limb passes beneath the first rib 
and then between the intermuscular bones of the second and third vertebrae, 
while the hypaxial limb passes over the first rib. In Katsuwonus the cutaneous 
artery is obviously narrower in calibre than the dorsal aorta, and the epaxial 
and hypaxial branches are much more separated from the lateral median line 
than in tunnies. The arterioles from these branches are given off at the surface 
of the body, between myotomes on both sides of each branch, dorsal and 
