Peridiniphycideans with a
tabulation which accords with, or clearly derives from, a pattern in which one or both of the following arrangements occur: (a) the first
apical plate (1') or its
homologue (*1') is asymmetrical, its
left lateral
triple junction being higher (i.e. more
anterior) than the
right lateral
triple junction; (b) there are two to four
fundital plates - always the
posterior intercalary plate (1p) and first
antapical plate (1'''') or their
homologues (*1p, *1''''), sometimes the
posterior sulcal homologue (*ps), and possibly in rare cases also the
right sulcal homologue (*rs) or subdivisions of these
plates. Among the
fundital plates, 1'''' (or *1'''') is almost always larger and is in a clearly more
dorsal position than the other(s).
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