342
KOHMAN Y. ARAKAWA
Remarks : According to Nakamura et al. (1963), the transverse section
of the rectum in this species is crescentic in outline.
78. Anodonta woodiana (Lea)
Owing to their loose and soft consistency, pellets of this species are
usually of indefinable shape. They may be in the form of an ungrooved
ribbon (Pellet-type ?III- 10).
Locality : Lake Shinji, Shimane, Japan.
Carditidae
It is characteristic of this family that the pellets are voided in the
shape of an ungrooved ribbon (Pellet-type 111-10).
79. Cardita leana Dkr (Pl. 2-16)
The faeces are voided in the form of a ribbon with no external
grooves. Superficially the ribbon is composed of rather coarse material
which is loose and fragile in consistency (Pellet-type 111-10).
Locality : Tomioka, Kumamoto, Japan.
Measurements: For an animal with a shell 34.0 mm long ribbons
average 0.31 mm in width.
Galeommidae (Galeommatidae)
This and the following families demonstrate a variety of pellettypes. I n some free-living species such as Scintilla japonica (Adams)
and Lasaea rubra (Montagu), the pellets are shed in the form of an
ellipsoid (Pellet-type 1-2), while in commensal forms such as Phlyctaenachlamys lysiosquillina (Popham), they are suggested to be discharged
as disjointed particles (Pellet-type 1 la).
80. Phlyctaenachlamys lysiosquillina (Popham)
“ T h e absence of mucous glands in the rectum is probably also
associated with this movement of water through the mantle cavity.
Particles of faecal matter will be shot out through the exhalent opening.
There is thus no necessity for the formation of firm faecal pellets,
because, owing to the violent expulsion of water, there will be less
danger of the mantle cavity silting up.” (Popham, 1939, p. 83.) (Pellettype l l a ) .
8 1. Scintilla japonica (Adams)
“ This species gives off ovoid pellets with twelve or thirteen constrictions, or sometimes without any surface-sculpturings. The pellets are
KOHMAN Y. ARAKAWA
Remarks : According to Nakamura et al. (1963), the transverse section
of the rectum in this species is crescentic in outline.
78. Anodonta woodiana (Lea)
Owing to their loose and soft consistency, pellets of this species are
usually of indefinable shape. They may be in the form of an ungrooved
ribbon (Pellet-type ?III- 10).
Locality : Lake Shinji, Shimane, Japan.
Carditidae
It is characteristic of this family that the pellets are voided in the
shape of an ungrooved ribbon (Pellet-type 111-10).
79. Cardita leana Dkr (Pl. 2-16)
The faeces are voided in the form of a ribbon with no external
grooves. Superficially the ribbon is composed of rather coarse material
which is loose and fragile in consistency (Pellet-type 111-10).
Locality : Tomioka, Kumamoto, Japan.
Measurements: For an animal with a shell 34.0 mm long ribbons
average 0.31 mm in width.
Galeommidae (Galeommatidae)
This and the following families demonstrate a variety of pellettypes. I n some free-living species such as Scintilla japonica (Adams)
and Lasaea rubra (Montagu), the pellets are shed in the form of an
ellipsoid (Pellet-type 1-2), while in commensal forms such as Phlyctaenachlamys lysiosquillina (Popham), they are suggested to be discharged
as disjointed particles (Pellet-type 1 la).
80. Phlyctaenachlamys lysiosquillina (Popham)
“ T h e absence of mucous glands in the rectum is probably also
associated with this movement of water through the mantle cavity.
Particles of faecal matter will be shot out through the exhalent opening.
There is thus no necessity for the formation of firm faecal pellets,
because, owing to the violent expulsion of water, there will be less
danger of the mantle cavity silting up.” (Popham, 1939, p. 83.) (Pellettype l l a ) .
8 1. Scintilla japonica (Adams)
“ This species gives off ovoid pellets with twelve or thirteen constrictions, or sometimes without any surface-sculpturings. The pellets are