of the cutaneous artery of the Thunnidae. In Katsuwonus the epaxial 

 and hypaxial arteries are nearly equal and originate from common lateral 

 branch of the dorsal aorta, in the hind part of the segment of the sixth 

 vertebra, just behind the pharyngeal muscle. 



In Euthynnus and Auxis there are two pairs of cutaneous arteries 

 originating from two different points. The anterior pair is smaller, 

 homologous to the hypaxial limb of the cutaneous artery of Katsuwonus , 

 and is given off from the body segment of the sixth vertebra. The 

 artery takes a more or less forward direction, passes through the 

 kidney and then turns forward. The artery has no relation with the 

 dark red muscle. The posterior pair is very thick, nearly as the 

 dorsal aorta or a little thicker than it, probably homologous to the 

 whole cutaneous artery of the Thunnidae. The posterior pair of cutaneous 

 arteries takes an obliquely upward and backward direction, and makes its 

 appearance at the surface of the body, between the intermuscular bones 

 of the fourth and fifth vertebrae." 



d. The Subcutaneous Veins of the Thunnidae 

 £\n JSnglishJ7 



"In the genus Thunnus , the most primitive type of the Flecostei, 

 the cutaneous system is best developed, and the vertebral system is 

 abortive, the posterior cardinal vein being wanting. A short, slender 

 caudal vein is found in the place of the posterior cardinal vein. The 

 caudal vein joins at the middle part to the transverse commissure of 

 the cutaneous veins and thus communicates indirectly with the Cuvierian 

 ducts. A pair of cutaneous veins, are found on each side of the body s 

 on the epaxial and hypaxial sides of the lateral median line. These 

 two veins run almost parallel, and quite near each other. They run 

 deep into the myotome of the fourth vertebra, at the hind margin of the 

 myotome, and unite a little below the surface of the body. The con- 

 fluent vessel runs obliquely anteriorly, passes under the proximal 

 slender part of the third rib, joins the Cuvierian duct of the respective 

 side, after collecting many renal venules. The right and left cutaneous 

 veins are united by a transverse commissure in the caudal portion,. This 

 transverse commissure of cutaneous veins is found in all the forms of 

 the Thunnidae - 



In P&rathunnus the cutaneous veins of both sides pass through the 

 myotome of the sixth vertebra, and each uniting to a large vein run- 

 ning below the fifth rib, pour into a transverse canal behind tne 

 pharyngeal muscles. The transverse canal joins the right Cuvierian 

 duct after uniting with a short renal vein. 



In Neo thunnus the cutaneous veins are united by an anterior 

 transverse commissure as in Parathunnus , or sometimes each of them 

 pours directly into the Cuvierian duct of the respective side as in 

 Thunnus ." 



e. The Subcutaneous Veins of the Katsuwonidae 



