Macrostomorpha taxonomy and phylogeny

The penis stilette is depicted as an irregular tube with a distal terminal splitting of the thickened walls. Taxonomically, M. lutheri is placed in species dubiae of the genus Macrostomum because of the unscientific methods used and the lack of material upon this animal. It is this present author's opinion that the stilette shown in figure is a greatly flattened and distorted stilette of Macrostomum bulbostylum mihi described in the same paper (GIEYSZTOR 1931). p. 143