SCATOLOGICAL STUDIES OF THE BIVALVIA (MOLLIJSCA)
343
dark brownish-green in colour, fine and homogeneous in texture, and
mostly composed of fine detritus containirlg unidentified microorganisms, algal fragments and some diatom frustules (Navicula,
Rhizosolenia, Coscinodiscus, etc.). The average proportion of length to
diameter of pellets shed by an animal with shell 1.3 ern long and
0.65 em high is 1.68 mm.”
Remarks : “ The description of pellets of this scintilloid mollusc with
illustrations was made by Arakawa (1962, p. 64) under the name of
Scintilla vitrea Quoy and Gaimard, 1832, with which the mollusc has
been identified by Japanem malacologists. Recently, however, Dr.
Tokubei Kuroda kindly inforrned me that this bivalve should be identified with 8. japonica (Adams, 1862), and hence the pellets are redescribed under the correct name ” (Pellet-type 1-1).
Measurements :
“ Diam. of pellet (mm) 0.50 0.48 0.46 0.34 0.33 0.50 0.46 0.33
Length of pellet (mm) 0.94 0.86 0.84 0.50 0.55 0.94 0.86 0.51
Lengthldiameter
1.88 1.79 1.82 1.47 1.66 1.88 1.46 1-54’’
(Arakawa, 1965, pp. 17-18.)
Erycinidae
82. Lasaea rubra (Montagu)
Morton (1956, p. 583, Fig. 8) has figured the pellets of this species
but without morphological description. The pellets may be shed in the
form of an elongate ellipsoid (Pellet-type 1-2).
Chamidae
Pellets of the representatives of this family may be released in the
form of a plain rod (Pellet-type 11-4).
83. Chama reJlexa Rve
is greenish-brown (Pellet-type 11-4).
Locality : Tomioka, Kumamoto, Japan.
Measurements: From a specimen of shell length 36.0 mm, rods are
1.8 mm broad.
This species releases rod-like pellets with fine texture. Pellet -colour
84. Pseudochama retroversa (Lischke) (Fig. 9 ~ )
Faecal pellets are shed in the form o f a rod with a soft consistency.
They are often cut on the surface by numerous occasional cracks. They
are fine in texture and brownish-grey in colour (Pellet-type 11-4).
343
dark brownish-green in colour, fine and homogeneous in texture, and
mostly composed of fine detritus containirlg unidentified microorganisms, algal fragments and some diatom frustules (Navicula,
Rhizosolenia, Coscinodiscus, etc.). The average proportion of length to
diameter of pellets shed by an animal with shell 1.3 ern long and
0.65 em high is 1.68 mm.”
Remarks : “ The description of pellets of this scintilloid mollusc with
illustrations was made by Arakawa (1962, p. 64) under the name of
Scintilla vitrea Quoy and Gaimard, 1832, with which the mollusc has
been identified by Japanem malacologists. Recently, however, Dr.
Tokubei Kuroda kindly inforrned me that this bivalve should be identified with 8. japonica (Adams, 1862), and hence the pellets are redescribed under the correct name ” (Pellet-type 1-1).
Measurements :
“ Diam. of pellet (mm) 0.50 0.48 0.46 0.34 0.33 0.50 0.46 0.33
Length of pellet (mm) 0.94 0.86 0.84 0.50 0.55 0.94 0.86 0.51
Lengthldiameter
1.88 1.79 1.82 1.47 1.66 1.88 1.46 1-54’’
(Arakawa, 1965, pp. 17-18.)
Erycinidae
82. Lasaea rubra (Montagu)
Morton (1956, p. 583, Fig. 8) has figured the pellets of this species
but without morphological description. The pellets may be shed in the
form of an elongate ellipsoid (Pellet-type 1-2).
Chamidae
Pellets of the representatives of this family may be released in the
form of a plain rod (Pellet-type 11-4).
83. Chama reJlexa Rve
is greenish-brown (Pellet-type 11-4).
Locality : Tomioka, Kumamoto, Japan.
Measurements: From a specimen of shell length 36.0 mm, rods are
1.8 mm broad.
This species releases rod-like pellets with fine texture. Pellet -colour
84. Pseudochama retroversa (Lischke) (Fig. 9 ~ )
Faecal pellets are shed in the form o f a rod with a soft consistency.
They are often cut on the surface by numerous occasional cracks. They
are fine in texture and brownish-grey in colour (Pellet-type 11-4).