Macrostomorpha taxonomy and phylogeny

Roughly crenated base. The termination is a very peculiar structure, three drawings of which are given better describe it (Fig. 22). Lateral, end, and dorsal views (a), (b), are shown. The sperm cell is a tapering filament which is possessed lateral setae in the posterior third of the cell. It is interesting note that the greatest number of sperm cells in this species is produced in the latter part of June, the warmest part of the summer in the Mountain Lake region.

The eyes are feebly developed (fig. 55) and some specimen are lacking them. p. 39