74 
PACIFIC SCIENCE, Vol, XVII, January 1963 
N 
36 ° 
34 ° 
32 ° 
30 ° 
28 ° 
Fig. 1. Index map for the position of submarine banks and other localities, a, Boso Peninsula; b, Izu Penin- j 
sula; c, Kii Peninsula. A, (Izu-) Oshima Is.; B, Hachijo Is.; C, Torishima Is.; D, Goto Islands; E, Amami- 
Oshima Is.; F, Kikaijima Is.; G, Okinoshima Is. in the Bungo Straits, a, Omurodashi (bank); P, Kurose 
(bank); 7 , Shinkurose (bank). (See Figs. 2 and 3 for details of areas I and II, respectively.) 
and several steep rocks are exposed above the 
sea surface. At Watarinose Bank, which lies 
between Kozu Island and Zenisu, the character 
of the bottom is supposedly generally the same 
as that at Zenisu. The neighboring waters of 
those banks are noted as excellent fishing 
grounds. Kurose and Shinkurose are the south- 
ern banks situated around Hachijo Island. The 
bottom characters of these two are known to 
be similar to that of Hyotanse. On the other 
hand, Omurodashi Bank off Izu-Oshima is said 
to be different from the others in having a 
sandy mud sediment at its top. 
The geographical positions of the submarine 
banks of Izu Islands under study are referred 
to in Figures 1 and 2. 
OCCURRENCE OF SPECIES BY AREA 
1. Hyotanse Bank 
material: Dredged by the R.V. "Soyo- 
maru” on Nov. 20 and 23, 1935, at 7 stations 
from depths of 118, 135, 140, 145, 148, 153, 
and 170-230 m. 
EARLIER WORKS: Niino (1955) reported 11 
