Molluscan Assemblages — Okutani 
75 
species of Pelecypoda and 5 species of Gastro- 
poda. Shirai (1958) reported 5 pelecypods and 
5 gastropods. 
SPECIES IN THE PRESENT MATERIAL: A car 
congenitum ( Smith ) ; Mimar carta aizoi Sakurai 
(ms), 137 m; Striarca fausta Habe, 137 m; 
Samacar pacifica (Nomura and Zimbo), 137 m; 
Barbatia tamikoae Sakurai (ms), 140 m; Pseu- 
do grammatodon obliquatus Yokoyama, var.; 
Nipponolimopsis decussata (A. Ad.), 145 m; 
Tucetona shinkurosensis Hatai, Niino and Ko- 
taka; Malleus irregularis ( Jousseaume) , var., 
118 m; Chlamys mollita (Rve. ), 118 m; C. lem- 
niscata (Rve.), 118 m; C. vesiculosus ( Dkr. ) ; 
C. tissotii (Bernard), 153 m; Spondylus anacan- 
thus (Mawe); Limatula japonica (A. Ad.); 
Lima fujitai Oyama; Septifer gray ana (Dkr.); 
Cardita nodulosa (Lamarck), 153 m; Gians sa- 
gamiensis Kuroda and Habe; Chama argentata 
Kuroda and Habe; Erigidocardium eos (Ku- 
roda), 140 m; Meiocardia tetragona (Ad. and 
Rve.); Emarginula fragilis Yokoyama, 153 m; 
E. teramachii Habe; Microgaza sp. aff. sericata 
Kira, 153 m; Talopena lifuana (Fischer), 153 m; 
Galeoastraea guttata (A. Ad.), 153 m; Ten- 
agodus anguinus (L.), 140 m; Serpulorbis me- 
dusae Pilsbry, 140 m; Apollon hirasei Kuroda 
and Habe, 145 m; Phanozesta semitort a Kuroda 
and Habe, 135 m; Latiaxis pagodus (A. Ad.), 
137 m; Bursa ranelloides (Rve.), var., 135 m; 
Mitrella sp. cf. lischkei (Smith); Conus gra- 
tacapy Pilsbry, 170 m; Conus sp., 153 m. 
OTHER SPECIES REPORTED BY NIINO: Euce- 
tona hanzawad (Nomura and Zimbo); Limop- 
sis tajimae (Yokoyama); Hawaiarca uwaensis 
(Yokoyama); Plicatula muricata (Sowerby); 
T richomus cuius coralliophaga (Gmelin); Lima 
basilanica (Ad. and Rve.), 260 m; Ctenoides 
annulata (Lamarck), 260 m; Pecten albicans 
(Schroter); Lucinoma spectabilis (Yokoyama); 
Perotrochus beyrichii ( Hilgendorf ) , 134, 160, 
128 m. 
MOLLUSCS REPORTED ONLY BY SHIRAI: Li- 
mopsis obliqua A. Ad., 250 m; Septifer excisus 
(Wiegmann), 104 m (this may be S. gray ana ) ; 
Eragum loochooanum Kira, 250 m (this may be 
Gians sagamiensis ) ; Galeoastraea millegranosa 
Habe, 260 m (this may be G. guttata ) ; Sil- 
iquaria cumin gii Morch, 260 m (this may be 
Tenagodus anguinus ). 
2. Zenisu Bank 
MATERIAL: Dredged by the R.V. "Soyo- 
maru” on Nov. 20, 1955, at 2 stations from 
depths of 85 and 170 m. 
EARLIER WORKS: Niino (1935) reported on 
the bottom character only. 
SPECIES IN THE THE PRESENT MATERIAL: 
Acar congenitum (Smith) ; Hawaiarca uwaensis 
(Yokoyama), 170 m; Pseudo grammatodon ob- 
liquatus (Yokoyama); Pectunculina cernata (A. 
Ad.); Limopsis cumingii A. Ad.; E ucetona 
shinkurosensis Hatai, Niino and Kotaka, 170 
m; Glycymeris rotunda (Dkr.); Polynemamus- 
sium intuscostatum (Yokoyama); Chlamys ve- 
siculosus Dkr.; C. tissotii (Bernardi); C. lem- 
niscata ( Rve. ) ; Plicatula muricata ( Sowerby ) ; 
Spondylus anacanthus (Mawe); Pecten albicans 
(Schroter); Lima zushiensis (Yokoyama); Vol- 
sella sp.; Pycnodonta musashiana (Yokoyama); 
Meiocardia tetragona (Ad. and Rve.); Frigido- 
cardium eos (Kuroda); Poromya flexuosa (Yo- 
N 
34 ° 30 ' 
34 ° 20 
34 ° 10 
34 ° 00 ’ 
33 ° 50 ' 
Fig. 2. Detail for I in Fig. 1. Dots indicate the 
biological stations for the R.V. "Soyo-maru” in Nov., 
1955. 
