northern region. It goes up mountain rivers and 
streams In June, spawning in October and Novem- 
ber, 
Oncorhynchus nerka (Walbaum) 
* Benimasu ” 
PL. XII, fig. 5. x, 
D. 11; A, 14 to 16; scales about 130, 
Length of body equal to about 4 times that of 
head, and 41 times depth of body, length of 
head equal to 4'/, times that of snout, and 4% 
times the diameter of eye. Body elliptical n shape 
and somewhat slenderer than that of O. keta (Wal- 
baum). Maxillary rather small, extending beyond 
eye. Teeth very small; vomer having about six 
weak teeth. Gill rakers very long and numerous. 
Flesh deep-red in colour. At spawning season 
male has an extravaganly hooked jaw. Body 
bright blue above and with a silvery lustre on 
the sides. The full-grown fish is without spots in 
spring, the young having very faint black spots 
on back. At the spawning season, it hecomes 
dark red. Length about 600 mm. Found only in 
Etorofu island, Hokkaido, in Japan. During June 
and July this fish ascends streams that have lakes 
at their headwaters, and the spawning takes 
place during the period from September to Oc- 
tober. 
Oncorhynchus tschawytscha (Walbaum) 
۰۶ Masunosuke 了 
PL. XII, fig. 6. 4 ½ 
D. 11; A. 14 to 17; seales 146, 
Body eorpulent and head rather pointed; maxi!- 
lary rather slender, reaching beyond eye. Eye 
and teeth rather small; vomerine teeth weaker 
than that of jaws, disappearing in males. In late 
Summer, jaws of males are produced and distorted 
and anterior teeth much enlarged, body then be- 
comes deeper, more compressed, and arched at 
shoulder. Ventral fins beginning behind middle of 
dorsal fin. Body dark blue above and silvery 
below, the back, dorsal and caudal fins being pro- 
fusely covered with small round spots. Body at- 
tains a length of 1500 mm. This species is seldom 
found in northern Hokkaido. It aseends large 
streams in Spring and Summer, spawning in Octo- 
ber and November, 
Oncorhynchus keta (Walbaum) 
„Sake 
PL, XII, fig. 1. male, fig. 2. female. % 
D. 9; A. 13 to 14; scales 140. 
Length of body equal to about 4 times that of 
head, and about 3 ½ times depth of body. Body 
oblong in shape; head somewhat elongated. Max- 
illary long, extending eonsiderably beyond posterior 
margin of eye. Gill rakers 20 to 25 in number 
and coarse. Caudal peduncle slender and long. 
Body dark indigo above and paler below ; body 
without defined spots; edges of fins somewhat 
darker than body. At spawning season, 
back becomes darker and appears brick red on 
sides, Body reaches a length of 900 mm. This 
is the commonest of the salmonoid species oc- 
eurring in Japan, being principally distributed on 
the north-eastern part of the eoast. It ascends the 
rivers, where it spawns during the season, which 
extends from October to January, and then perishes 
from exhaustion. The fry descends the river in 
June, and grows in the sea where it spends about 
4 years, at the end of which it has matured. 
Oncorhychus gorbuscha (Walbaum) 
“ Karafutomasu " 
PL. XII, fig. 3, * 71 
D. 11; A. 15; scales 185 to 217. 
Body somewhat slender and covered with very 
small scales. In Autumn body of the full-grown 
male becomes very compressed, with a very high 
hump above the shoulder, the jaws being much 
elongated and conspicuously hooked, with very 
strong canines in front. Body blue above, with 
a silvery lustre on the sides; back and tail with 
numerous large oblong black spots, those on caudal 
fin being very large. Average length 380 mm, 
This species is found on the coasts and in the 
streams of the northern Pacifie; in Japan it occurs 
from Saghalien southwards to north-eastern Hok- 
kaido. 1t ascends the streams of north-eastern 
Hokkaido in July. 
Oncorhynchus masou (Brevoort) 
“ Masu ” 
PL. XII, fig. 4. TA 
D. 14 to 15; A. 14 to 15; scales 125 to 130. 
Length of body equal to about 4 to 4*/, times 
that of head, and about 3% times the greatest 
depth of body; length of head equal to about 3% 
times depth of caudal peduncle, 3% times length 
of snout, and 7 times the diameter of eye. Body 
sub-similar in shape to that of O. keta (Wal- 
baum), but snout shorter and blunter, and in- 
sertion of dorsal fin more anterior. Gill rakers 
comparatively short and 18 in number. Body dark 
blue above, silvery white on the sides. Length 
600 mm. This species is widely distributed through- 
out Japan, being especially abundant in the 
* 
Oncorhynchus nerka (Walbaum) 
(H= EM) xf, 
D. 11; A. 14 to 16; scales 130. 
meae 44m, BED 40/46 0,1 MEE 
D 4% fr, MERO 47/, f O. ۵۱2۲ ^ CERE L 
TL LO RRP TERO. BE 
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t HERE 87 BV. BRAD. WERKE 0. HE 
REWE zi MEO ETE L CR. ETP BE 
MTEC LTE DV. IF MM LOL 
FERNE LOLHO. REIN Ip rc 
Mera K K D. few 600 ETHET. AR DA N 
Yn, TDA AMARA ماه‎ A AICI BE 
Hob HERR CET ADA. XH Lët i · & x EF 
zziz EG SES 0. MMIC TE C JI] 
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FS. wt BK OE BELT PE ND 
+ [۱-11 2۰ Wat LT NEN O. A 
"CX 6 Mid ۰ 
TASAS 
Oncorhynchus tschawytscha (Walbaum) 
[第 十 二 图 版 ”第 上 图 ) x 
D. 11; A. 14 to 17; seales 146, 
EMRL, Mama EAN N E L 
ACHMED. IRA NE EVN 5 . ETAR Ou 
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+ ke 
Oncorhynchus kata (Walbaum) 
lie "CHE, 2-8 UE) ۸ 
D. 9; A. 13 to 14; seales 140. 
i L E 4 ۲۰ ۷۵ ED 3'/. ERD. ۵۱ AIT 
ولا‎ BÜHNE aD, KARA CERRO ET 
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سا‎ Wii alc عتما‎ FH I سا‎ 
FEAR MCE D REEL, Ad J 27r 0, HF 
WHEEL, MMIC AOR E HET. BE 
900 ۷۱2367۰ KERIB > AACE PICT It 
PAVIE D ARE IC. -N ORE 
— 00110102 MINCE L, Sau REIT. ME 
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Z 18:5 [- 8 كك‎ 0 LORD. 
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Oncorhynchus gorbuscha (Walbaum) 
Cs d- — Wu Bi) ENG 
D. 11; A. 15; seales 185 to 217. 
ne CEPI EE ¢, fer] O. BK SEICE UE ME 2 RE 
مالس دا‎ f at L n K „ HHC JM: 
n L, AS ۱ NT L. E x fir 
Ice ج ناعم‎ Af. METIO DER عاك‎ 
Lara, 2 ORE 275 EOS NH 
L, ERICH Stoen. < MED b 
Oc LT 890 8 ۸۹۰۰ KEIER FATE L, 8 
TR DAA EL. ERIC Es. 
Ka A 
Oncorhynehos masou (Brevoort) 
CA a) ۶ 
D. 14 to 15, A. 14 to 15, seales 125 to 130. 
REGER Aë 4'/.45, BF O 3 / D. 
HERERO SD 3/54, Wao 42/14 IRA D 7 
iro. MIB EC الا لا‎ ES. EE 4 Hing K 
e AT ERIT br n b WEA ei, TERA OF 
L. PASH ¢, Hb RUE D HN b 
b. WHO > ILO Me iL. HF ff 
^, FRGERAGE 0. Fee. 体 甚 600 
PECET. AN NEH ARTE dE ERE Ié E 
L AAMT سا‎ 4-84 ۷۰1-11122802 ENGEL 
CHIT. ROMINA BDA Ic o E 1000 7j 
E 2000 HED b. ARENA E ER 9 + 
