368
KOHMAN Y . ARAKAWA
Locality : Hiroshima Bay, Japan.
Measurements when size of producer is 19.0 mm in shell length :
Length of ovoid pieces (mm)
0.55 0.50 0.65 0.55
Ratio lengthlbreadth
1.38 1.11 1.63 1.38
Breadth of ovoid pieces (mm)
0.40 0.45 0.40 0.40
Myidae
157. M y a truncata L.
marked with a single dextral spiral groove (Pellet-type 11-5).
Moore (1931, p. 286) has briefly stated that the faecal rods are
158. iVf. (Arenomya) japonicn Jay (Fig. 1 1 ~ )
They are
usually cut by numerous occasional clefts. They are fine in texture,
soft in consistency and greyish-brown in colour (Pellet-type 11-5).
Locality : Otoshima, Tamashima, Okayama, Japan.
Measurements : Breadth of the faecal rods fluctuates between 0.90 and
1-20 mm, for an animal with a 75.0 mm-long shell.
Faecal rods are sculptured by a single spiral groove.
Corbulidae
The pellets described here for two representatives of this group
belong to Pellet-type 11-4.
159. Varicorbula bifrons (A. Ad.)
carrying a considerable amount of viscous matter (Pellet-type 11-4).
Locality : Tomioka, Kumamoto, Japan.
Measurements: For a specimen with a shell 3.6 mm long, pellets
average 0.18 mm in breadth.
Faecal rods are soft, frail and coarse in texture. They are shed
160. Anisocorbula venusta (Gould)
Pellets are shed in the form of a short rod (Pellet-type
Locality : Tomioka, Kumamoto, Japan.
Measurements: For an animal with an 8-5 mm-long shell
are 0.11 nim broad.
1-4).
the pellets