9. THE CLASS CRUSTACEA
313
long, fourth thoracic segment 0.080 mm long, fifth thoracic segment
0.064 mm long, sixth thoracic segment 0.136 mm long; genital and
abdominal segments each armed with a row of minute spines along
posteroventral margin but unarmed dorsally ; caudal ramus, 0.029 mm
x 0.025 mm, slightly wider than long, with longest terminal seta,
which may be partially retracted, measuring 0.336 mm ; two additional
setae present on ramus; egg sac dorsoventrally flattened, 0.290 mm
long x 0.270 mm wide x 0-120 mm thick, reaching bases of caudal
FIGS. 210 and 211. Tisbe celutu adults. (210) Female, dorsal view; (211) thorax and
abdomen of male, dorsal view. (Redrawn after Humes, 1954a.)
rami, contains about forty-five eggs, each about 0-054 mm in diameter ;
first antenna of eight segments measuring 0.038, 0.060, 0.044, 0.027,
0.015, 0.014, 0.010 and 0.028 mm long respectively; fourth segment
with aesthetask, 0.125 mm long, extending well beyond tip of antenna;
second antenna with four segments of endopodite somewhat indistinctly
separated ; first swimming leg with exopodite shorter than endopodite,
bent at an angle so as to cross behind endopodite, endopodite podomeres measure 0.082, 0.081 and 0.007 mm respectively, exopodite
podomeres measure 0.045, 0.045 and 0.020 mm respectively ; second,
313
long, fourth thoracic segment 0.080 mm long, fifth thoracic segment
0.064 mm long, sixth thoracic segment 0.136 mm long; genital and
abdominal segments each armed with a row of minute spines along
posteroventral margin but unarmed dorsally ; caudal ramus, 0.029 mm
x 0.025 mm, slightly wider than long, with longest terminal seta,
which may be partially retracted, measuring 0.336 mm ; two additional
setae present on ramus; egg sac dorsoventrally flattened, 0.290 mm
long x 0.270 mm wide x 0-120 mm thick, reaching bases of caudal
FIGS. 210 and 211. Tisbe celutu adults. (210) Female, dorsal view; (211) thorax and
abdomen of male, dorsal view. (Redrawn after Humes, 1954a.)
rami, contains about forty-five eggs, each about 0-054 mm in diameter ;
first antenna of eight segments measuring 0.038, 0.060, 0.044, 0.027,
0.015, 0.014, 0.010 and 0.028 mm long respectively; fourth segment
with aesthetask, 0.125 mm long, extending well beyond tip of antenna;
second antenna with four segments of endopodite somewhat indistinctly
separated ; first swimming leg with exopodite shorter than endopodite,
bent at an angle so as to cross behind endopodite, endopodite podomeres measure 0.082, 0.081 and 0.007 mm respectively, exopodite
podomeres measure 0.045, 0.045 and 0.020 mm respectively ; second,