358
KOHMAN Y. ARAKAWA
Measurements when size of producer is 5.5 mm in shell length :
Length of pellet (mm) 0.14 0.16 0.16 0.17
Breadth of pellet (mm) 0.09 0.09 0.09 0.09
Ratio length/breadth
1.56 1-78 1.78 1-89
Measurements when size of producer is 5.0 mm in shell length :
Length of pellet (mm) 0.24 0.22 0.20 0.22 0.18 0.21
Breadth of pellet (mm) 0-13 0.12 0.11 0.12 0.11 0.12
Ratio length/breadth
1.85 1-83 1.82 1.83 1.64 1.75
Tellinidae
The representatives in the Tellinidae which have so far been
examined defecate either discoid (I-la) or ovoid (1-1) pellets, or rarely,
constricted rod (IA-3). The pellets are usually made up almost entirely
of compact detritus with uniform consistency and may be separated
by the length/breadth ratios among species of the different genera ;
e.g. in Tellina this is, as a rule, more than 1 and less than 2 ; in Macoma
it is less than 1.
129. Arcopagia crassa Pennant
“ The pellet is smooth and sandy in appearance, and light or dark
brown in colour, often pellets of both shades being shed by the same
animal within a short period. Occasionally the pellet is voided in the
form of a rod, but most frequently this is constricted and cut up into
the typical rounded ended pellets. I n section these show no localization
of the constituent materials, and are formed from detritus containing
numerous spicules, and diatom remains. From an animal with a shell
1.3 cm long, the pellets average 0.33 mm in diameter, and have a ratio
of length/breadth = 1.35.” (Moore, 1931, p. 282, P1. 30, Fig. 1.) (Pellettype 1-1 (?IA-3)).
130. Moerella donacina (L.)
“ The above description (Arcopagia crassa) may be applied to this
species, except that here the ends are less rounded, and there is a
tendency to the formation of rather irregular pellets. From an animal
with a shell 1.5 cm long, the pellets average 0.36 mm in diameter, and
the ratio lengthlbreadth = 1.30.” (Moore, 1931, p. 282, P1. 30, Fig. 2.)
(Pellet-type 1-1 (?IA-3)).
131. M . kurodai (Makiyama) (Pl. 5-60)
averages 1.92 (Pellet-type 1-1 (12)).
Pellets are oval with rounded ends. The length/breadth ratio
KOHMAN Y. ARAKAWA
Measurements when size of producer is 5.5 mm in shell length :
Length of pellet (mm) 0.14 0.16 0.16 0.17
Breadth of pellet (mm) 0.09 0.09 0.09 0.09
Ratio length/breadth
1.56 1-78 1.78 1-89
Measurements when size of producer is 5.0 mm in shell length :
Length of pellet (mm) 0.24 0.22 0.20 0.22 0.18 0.21
Breadth of pellet (mm) 0-13 0.12 0.11 0.12 0.11 0.12
Ratio length/breadth
1.85 1-83 1.82 1.83 1.64 1.75
Tellinidae
The representatives in the Tellinidae which have so far been
examined defecate either discoid (I-la) or ovoid (1-1) pellets, or rarely,
constricted rod (IA-3). The pellets are usually made up almost entirely
of compact detritus with uniform consistency and may be separated
by the length/breadth ratios among species of the different genera ;
e.g. in Tellina this is, as a rule, more than 1 and less than 2 ; in Macoma
it is less than 1.
129. Arcopagia crassa Pennant
“ The pellet is smooth and sandy in appearance, and light or dark
brown in colour, often pellets of both shades being shed by the same
animal within a short period. Occasionally the pellet is voided in the
form of a rod, but most frequently this is constricted and cut up into
the typical rounded ended pellets. I n section these show no localization
of the constituent materials, and are formed from detritus containing
numerous spicules, and diatom remains. From an animal with a shell
1.3 cm long, the pellets average 0.33 mm in diameter, and have a ratio
of length/breadth = 1.35.” (Moore, 1931, p. 282, P1. 30, Fig. 1.) (Pellettype 1-1 (?IA-3)).
130. Moerella donacina (L.)
“ The above description (Arcopagia crassa) may be applied to this
species, except that here the ends are less rounded, and there is a
tendency to the formation of rather irregular pellets. From an animal
with a shell 1.5 cm long, the pellets average 0.36 mm in diameter, and
the ratio lengthlbreadth = 1.30.” (Moore, 1931, p. 282, P1. 30, Fig. 2.)
(Pellet-type 1-1 (?IA-3)).
131. M . kurodai (Makiyama) (Pl. 5-60)
averages 1.92 (Pellet-type 1-1 (12)).
Pellets are oval with rounded ends. The length/breadth ratio