PERISTOME HOMOLOGY IN MIELICHHOFERIA AND A TAXONOMIC ACCOUNT OF NORTH AMERICAN SPECIES

抄録

  Although traditionally considered single and endostomial, the peristome of Mielichhoferia mielichhoferiana is actually double, consisting of more or less well-developed exostome teeth as well as a delicate, more or less adherent endostomial basal membrane. M. macrocarpa has short, linear exostome teeth but no endostome. Since M. mielichhoferiana is the type of the genus Mielichhoferia and different species of the genus exhibit single peristomes of endostomial or exostomial structure and also double peristomes, it is impossible to define the more recent Haplodontium on the basis of single, exostomial peristomes. Mielichhoferia is presented here in an inclusive sense, and nomenclatural transfers are provided for 10 species previously referred to Haplodontium. The three North American taxa (M. mielichhoferiana, M. macrocarpa, and M. tehamensis) are described in detail; M. elongata is considered a synonym of M. mielichhoferiana.