TAB. IV. 
Fig. 10. Cythereis qiiadrilatera, continued. 
0 
X 
50 
Adult, perfect, anterior aspect 
Gault. 
Folkstone. 
h 
X 
50 
Immature, left valve, outside 
33 
i 
X 
50 
Immature, left valve, outside 
5? 
33 
i' 
X 
50 
Immature, perfect, dorsal aspect . 
?? 
33 
j 
X 
50 
Young, right valve, outside 
?? 
33 
f 
J 
X 
50 
Young, perfect, dorsal aspect 
Detritus. 
Cliar-ing. 
Fig. 1 1 . Cythereis ciliata. 
a 
X 
50 
Adult, left valve, outside 
Detritus. 
Charing. 
h 
X 
50 
Adult, perfeet, placed obliquely, left valve 
upwards 
3 J 
33 
c 
X 
50 
Adult, perfect, dorsal aspect 
3? 
3 3 
d 
X 
50 
Adult, perfect, ventral aspect 
33 
33 
e 
X 
50 
Adult, perfect, anterior aspect 
33 
33 
f X 
50 
Immature, left valve, outside 
Gault. 
Folkstone. 
9 
X 
50 
Young, left valve, outside . 
35 
33 
/ 
X 
50 
Young, perfect, dorsal aspect 
33 
33 
h 
X 
50 
Young, left valve, outside . 
33 
33 
h' 
X 
50 
Young, perfect, dorsal aspect 
Detritus. 
Cliaring. 
