particularly on the back where about three transverse stripes are also visible. 

 The first dorsal fin is black and the ventral fins are slightly blackish, while the 

 second dorsal, pectorals, anal, and caudal fins are almost colorless. Inside of 

 the body many melanophores can be seen on the walls of the body cavity, around the 

 spinal column, on the gill arches, and on the gill filaments. One of these speci- 

 mens, which may perhaps be big-eyed tuna [[ Farathunnus mebachl j. had eaten a 16 mm 

 larval fish of another species., 



A 36 mm juvenile tuna (Figure 7) was recovered from the stomach of a dolphin 

 which was taken off Gaja I. £29°54'N, 129°33'E] on May 24, 1925. This specimen also 

 cannot be clearly identified as to genus and species. Its form and bodily propor- 

 tions are roughly the same as those of mature fish, but the eyes and the mouth are 

 slightly larger than in adult specimens. The length of the head is equal to one- 

 third of the body length excluding the caudal fin and to one and one-fourth times 

 the body depth. The length of the snout is approximately equal to the diameter of 

 the eye. About six spines are set closely together at the angle of the preopercle 

 with their basal portions coalescent so that this portion of the bone is produced 

 posteriorly like the preopercle of cybiids. The spines on the surface are obscure. 

 On the first gill arch there arc four gill-rakers on the epibranchial, 15 on the 

 ceratobranchial, and one on the hypobranchial. Twelve teeth can be seen on the gill- 

 rakers of the ceratobranchial. There are 24 teeth in the upper jaw, over 30 in the 

 lower jaw, nine on the palatine bone, and some on the pharyngeals. No teeth are 

 visible yet on the vomer and me so pterygoid. The posterior half of the postclavicle 

 in this specimen, as in that described just previously, is almost wholly flat and 

 straight, however, it tapers gradually from the anterior lamellate portion to the 

 posterior needle-shaped part so that the line of demarcation between the two parts 

 is not clear. The coloration of this juvenile is rather dark. The first dorsal is,, 

 of course, black, and so is the second dorsal. The pectorals and the caudal are 

 also slightly blackish, but the ventral and annl fins are almost colorless. Parti- 

 cularly notable are the approximately five transverse stripes which appear on the 

 sides of the body, one immediately posterior to the head, two ventral to the first 

 dorsal fin, one between the first and second dorsals, and one ventral to the second 

 dorsal. This specimen differs on various points from the one described just pre- 

 viously, and it is thought to be of a different species. It may perhaps be a yel- 

 lowfin (" Neothunnus macropterus j. 



Yellowf in Tuna Qfeothunnus macropterusj 



A juvenile fish 63 mm long (excluding the caudal) and 12 mm deep was recovered 

 from the stomach of a skipjack taken at Gonsone May 26, 1925. It was difficult to 

 study because the skin was missing and the viscera were much damaged, but the 

 vertebral count showed that it was clearly a thunnid, and on the basis of the gill- 

 raker count of 8 +(15 + 7) it was judged to be a yellowf in. There are some fine 

 teeth grouped along the long axis of the vomer and there are six teeth arranged in 

 two rows on the mesopterygoid. The palatine also has some teeth. The anterior 

 half of the postclavicle is 4.05 mm long and 2.30 mm broad; the posterior half is 

 missing. Inferior foramina can be seen in all the vertebrae posterior to the third 

 caudal vertebra. 



A specimen which was recovered by Mr. Gisuke Umemoto from the stomach of a 

 skipjack taken at Gogosone [29°30'N, 129°5 I E] May 10, 1924 was reported on page 91 

 of the preceding number of this journal* From the vertebral count and the presence 

 of inferior foramina in the vertebrae posterior to the second caudal vertebra it 

 appears to be a yellowf in. Eesides the upper and lower jaws, there are teeth on 

 the vomer, palatine, and mesopterygoid. There is an air bladder. The anterior half 



-5. 



