Dear jr.;-
    Among the wentletraps, we have a similar situation. In 1844, G.B.
Sowerby (Either I, II, or III or a combination of all three)
published both E. dubia and irregularis as different species. I have
always maintained that the Sowerbys MUST have seen actual differences
in the two. But people more knowledgeable than me (and bigger and
stronger) have declared the two species to be only one. One question
remaining is: so which one is it? We sem to have decided that
irregularis is THE one---for no good reason I can think of. The
reason the Sowerbys counted them as two may be that just like among
the human species, there are individual diffences. In some species
like E. lamellosum, the differences may be quite wide and lead to the
publication of (in that case) about 20 synonyms. Some species are
just more variable than others.
              Art