324
KOHMAN P. ARARAWA
are greyish-green in colour and very coarse and soft in consistency.
They are cut by numerous transverse clefts (Pellet-type 11-4).
Locality : Japan Trench (1 280 m in depth).
Measurements : For an animal with shell 23.0 mm long, the breadth of
the faecal rods averages 0.20 mm, and for one with shell 30.5 mm long,
0.38 mm.
Mytilidae
Almost all the representatives of this family from which faecal
pellets have so far been examined produce sculptured ribbons which
are referable to Pellet-type 10a.
24. Mytilus californianus Conrad
“ I n cross-section, the ribbon-like faeces of the oyster and mussel
showed marked longitudinal grooves and ridges.” (Edge, 1934, p. 80,
Fig. 2.) (Pellet-type III-l0a).
25. M . coruscus Gould
“ The faecal pellets are in the form of a ribbon with two free edges
rolled gently upwards to bear a crescent section and without any external sculptures. They are so delicate that they are usually voided
broken into much shorter pieces. They are brownish green in colour
and fine and homogeneous in surface texture. For an animal with
shell 4.55 cm long, the ribbons average 0.54 mm in width.” (Arakawa,
1963, p. 205, Text-figs. 6 A-B.) (Pellet-type III-IOU).
26. M . galloprovincialis Lam. (Fig. 4 centre)
of M . edulis (Pellet-type III-l0a).
Locality : Ondo, Hiroshima, Japan.
Measurements: Ribbons shed by an animal in the shell 75-0 mm long
average 1.3 mm in width.
27. M . edulis L.
“ The faeces are discharged through the exhalant siphon. They are
in the form of a ribbon having characteristic longitudinal folds. . . .
The actual width would be from ca 1.5 mm to ca 0.75 mm. Ribbons of
2 mm or even wider are sometimes seen. The characteristic folds are
determined by the shape of the anus through which the soft mass is
propelled. This opening is more or less similar in shape to that of a
Ribbons of this species are very similar in nature and form to those
KOHMAN P. ARARAWA
are greyish-green in colour and very coarse and soft in consistency.
They are cut by numerous transverse clefts (Pellet-type 11-4).
Locality : Japan Trench (1 280 m in depth).
Measurements : For an animal with shell 23.0 mm long, the breadth of
the faecal rods averages 0.20 mm, and for one with shell 30.5 mm long,
0.38 mm.
Mytilidae
Almost all the representatives of this family from which faecal
pellets have so far been examined produce sculptured ribbons which
are referable to Pellet-type 10a.
24. Mytilus californianus Conrad
“ I n cross-section, the ribbon-like faeces of the oyster and mussel
showed marked longitudinal grooves and ridges.” (Edge, 1934, p. 80,
Fig. 2.) (Pellet-type III-l0a).
25. M . coruscus Gould
“ The faecal pellets are in the form of a ribbon with two free edges
rolled gently upwards to bear a crescent section and without any external sculptures. They are so delicate that they are usually voided
broken into much shorter pieces. They are brownish green in colour
and fine and homogeneous in surface texture. For an animal with
shell 4.55 cm long, the ribbons average 0.54 mm in width.” (Arakawa,
1963, p. 205, Text-figs. 6 A-B.) (Pellet-type III-IOU).
26. M . galloprovincialis Lam. (Fig. 4 centre)
of M . edulis (Pellet-type III-l0a).
Locality : Ondo, Hiroshima, Japan.
Measurements: Ribbons shed by an animal in the shell 75-0 mm long
average 1.3 mm in width.
27. M . edulis L.
“ The faeces are discharged through the exhalant siphon. They are
in the form of a ribbon having characteristic longitudinal folds. . . .
The actual width would be from ca 1.5 mm to ca 0.75 mm. Ribbons of
2 mm or even wider are sometimes seen. The characteristic folds are
determined by the shape of the anus through which the soft mass is
propelled. This opening is more or less similar in shape to that of a
Ribbons of this species are very similar in nature and form to those