quiz (taxonomy)

[Doug Yanega]

Servio wrote:

>The best solution is to regard it as species inquirenda. Doing so, you are
>declaring  that  the name remain valid but it is necessary to clarify the
>species identity problem. If someone discover a type or any other cue to the
>species identity, it will be simple to attribute the name to the species. On
>the other hand, if declare it as a nomen dubium, you are definitively
>declaring that this name, although available, should not be used for any
>species, as it is applicable to anything.

This has direct bearing on a situation I have encountered - there is a fly
species named by Macquart in 1851, for which the unique type is lost and
the original description problematic (it includes the description of a
structure which quite definitely does not exist in any fly species).
However, the remaining features in the description *are* sufficient to
associate it to one of two extant species, both unnamed (as things stand),
one of which is geographically closer to where Macquart's specimen came
from.
        Given that there appear to be two taxa which *could* be Macquart's
species, and that these also fail to match the description (thanks to his
inclusion of a non-existent structure), designation of a neotype doesn't
seem entirely appropriate. Likewise, there is apparently no hope of the
type being discovered, or anything else to allow an unambiguous choice
between the two extant taxa (a geographic association is a pretty weak
basis), so I doubt anything can "clarify the species identity problem", and
species inquirenda is probably out, as well. It would seem to me that
declaring it a nomen dubium would be the best choice, and that new species
names should be given to the two taxa at hand.
        But now, a twist: Macquart's species is the only described species
in its genus (which also happens to be the genus upon which the family name
is based). Am I correct in presuming that if I designate Macquart's name to
be a nomen dubium, that I must designate one of the two newly-named species
to be the type species of the genus? Or *should* I just go ahead and
designate a neotype, preserving Macquart's name, knowing that there's no
way anything is going to turn up to clearly contradict such a designation?

Thanks,

Doug Yanega    Depto. de Biologia Geral, Instituto de Ciencias Biologicas,
Univ. Fed. de Minas Gerais, Cx.P. 486, 30.161-970 Belo Horizonte, MG   BRAZIL
phone: 31-499-2579, fax: 31-499-2567  (from U.S., prefix 011-55)
                  http://www.icb.ufmg.br/~dyanega/
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82