124 EUG. DADAY DE DEÉS 
Par la forme des valves et la structure de la tête de la femelle, 
celte espèce rappelle beaucoup Caenestheriella Joubini Dad., 
mais elle en diffère par la surface des valves, les épines margi- 
nales du telson et surtout par les segments postérieurs du tronc 
et l'enveloppe de l'œuf. Une autre différence consiste en ce 
que le bord de l’épipodite branchial des pattes est dentelé et 
non lisse comme chez Ca nestheriella Joubini Dad. 
D'après la seule localité connue jusqu'à ce jour, la distribution 
géographique de Gaenestheriella vidua Dad. est limitée par 
les 26° 40° de longitude orientale, les 300 50" de latitude méri- 
dionale et les zones isothermes + 18 à + 20. 
Caenestheriella gifuensis (Ish.). 
Fig. 22, a-f. 
Estheria gifuensis Ishikawa C., 64, p. 3, Tab., 5, fig. 1-12. 
« Shall valves thin, amber coloured oblong-oval, about two- 
thirds as broad as long, the anterior edge more rounded than 
the posterior. The beak small but rather prominent, situated at 
about one-fourth from the anterior edge of the shell; the dorsal 
edge behind the beak quite straight Hill Co the posterior fourth 
of the shell, where it suddenly slopes down. About fifteen to 
seventeen lines of growth, with à row of coarse setae along the 
seven or eight marginal lines. Another row of smaller and 
denser setae at the edge of the shell, situated a little beyond the 
larger ones, the tips of these larger setae at the edge of the 
shell beimg hooked. The supporting pillars situated in the cel- 
lular matrix of the shell appear as fine punctations under a 
low magnification. Under à high power these punctations ap- 
pear as slar-shaped figures as has been observed by varous 
other authors. These star-shaped structures disapear along the 
free edge of the shell, wehre à number of clear oval or irregular 
markings are to be seen. The outermost of these form a single 
row at some distance from the edge of the shell and running 
parallel with it. The other markings are either scattered irre- 
gulariy, or arranged in parallel rows and confluent with the ou- 
termost ones. These are also found along all the lines of growth, 
but less distinctiv. » 
