Gaxmus Buthymw ( yatio^xoku ) 



This genus resembles Katsuironus, but is a degenerate group. It ooouples a 

 position between the gener» ~katsuwonu8 and Auxls* The mouth is rather large and 

 the teeth are better developed than in Katsvnronus em.d Auxls. The inferior branohes 

 of the suboutaneous lateral blood vessels have disappeared, and the oage formed by 

 the haemal spines around the blaok bloody tissue is not as firm as in the sklpjaok* 

 There are two species in the Paoifio and one in the Atlantic. Only the Atleintio 

 species has been known hitherto. 



Euthymius yalto n.sp. (yaito ) 



Called jal tostaaa J .n Wakayama, yahara in Mle, watanabe , suma , segatsno, and 

 uramawarigatsua in lyushu, and hlragatauo In MiyasalB.. 



D. 15 or 16, 12 or 13, 8. A. 15, 7. Vert. 20 / 19. Gill-rakers 10 / 24. 



In the past this species has been considered to be identical with that of the 

 Atlantic, but It is distinguished from Euth . thunnlna by the presence of vomerine 

 teeth, by the oblique, markings on the baok, and by the absence of longitudinal 

 stripes above the lateral line* 



The coloration of the baok ranges from blaok to indigo with mcmy irregularly- 

 shaped spots. The fins emd f Inlets are black or gray, and there are several blaok 

 spots on the pectoral region. Individuals are seen which are over 2 feet long and 

 weigh about 8.27 pounds. These fish appear occasionally in our southern waters, 

 but they are not abimdant. They have be«n found as far north a^ Chiba Prefecture, 

 but the northern limit of their distribution Is not clearly known. No instance of 

 their occurrence in the Japan Sea has been reported. 



This species may be Identical with that which Cantor collected at Plnan 

 [Penang?] in India and which he named Thyxannua af finis, however, he did not mention 

 vomerine teeth and only described the outward 'appearance of the fish so it is impos- 

 sible to decide this point. 



G«nnuB Auxls (mejlka-zoku) 



This group is even more degenerate than Euthynnue , and aooordingly differs 

 widely from the other thuxmids. The haemal spines of the thoracic vertebrae do not 

 form a haemal arch, the first vertebra is not fused to the oranlum, and the first 

 and second dorsals are not continuous. There is no air bladder. It is a small 

 fish about one foot long, the snout is short, and the coloration is roughly the same 

 as that of E. yalto , however, ther« are no spots below the pectoral fin. The 

 species ooo'urs in both the Atlantic and the Pacific* 



There are two species in Japanese waters which are distinguished by differences 

 in the number of scales on the lateral line cmd in the breadth of the body, how- 

 ever, they are oooaelonally found mingled together and are bo'tii known by the same 

 names of ■ajika, iSiaag»t«uo, kogaf uo, and fukorai . 



Auxls hira n.sp. (hiramejika ) 



Called hiragatauo , hlraeoda , soma , and suma in Wakayama, oboso , subo » and 

 shibuwa in Shituoka, and Tobukura * 



D. 10 or 11, 12, &• A. 13, 7. Oill-rakers 9/30, 



IS 



