121
Mukai et al. 1997 ). Some (Powell 1967 ; Viskova 1992 ) also
accepted the changes in terminology made by Silén, who
used the term “ectooecium” for the entire ooecial fold and
“entooecium” for the ooecial vesicle (criticized by Ryland
1968 ). Notably, Calvet had called the ooecial vesicle a
“vésicule ovicellienne inférieure”, Levinsen ( 1909 ) an
“ooecial operculum”, Harmer ( 1926 ) a “membranous vesicle”, Cori ( 1941 ) “Untere Blasé des Ooeciums”, Silén
( 1944 ) “interior vesicle”, and Ryland ( 1970 ) an “inner vesicle”. The common term “ooecial vesicle” was introduced by
Woollacott and Zimmer ( 1972a ), and later Banta ( 1977 ) and
Santagata and Banta ( 1996 ) used “median vesicle” and
“ovicell plug” for this structure correspondingly.
Interestingly, fi gures 1–8a from Silén’s ( 1945 ) paper,
often reproduced, have never been modifi ed, whereas the
communication pore to the ooecium in fi gure 10 of Calvet
Fig. 2.4 Silén’s ( 1944 ) schematics of ovicell structure in Scrupocellaria
scabra : ( A ) longitudinal section of an ovicell in a decalcifi ed specimen.
( B ) Diagrammatic reconstruction of the section. Abbreviations: chev
ectooecium, chiv sclerite of ooecial vesicle, co brood cavity, cv ooecial
coelomic cavity, di diaphragm, dz daughter (distal) zooid, eph distal
part of ooecial vesicle, fm frontal membrane of daughter zooid, iv inner
(ooecial) vesicle, m muscles of ooecial vesicle, op operculum, pol distal
end of tentacle sheath, ve vestibulum
2.1 History of Studies of Cheilostome Brood Chambers