ABSTRACT
Diplodinium (sub-genus Polyplastron) multivesi-culatum (Dogiel and Fedorowa, 1925) undoubtedly is one of the most interesting representatives of the Infusorian family Ophryoscolecidae (which occurs in the stomachs of ruminants), especially from the systematic and phylogenetic standpoint. The origin of this species shows some peculiar causes which are operative in the development of these Infusorian species, but besides that the present treatise points out some new aspects regarding the development of new species in general.
The identity of the characteristics enumerated here relating the P. multivesiculatum and P. hegneri having already been mentioned before.
By using chlor-zinc-iodide or a combination iodine-alcohol and con centrated H2SO4 one can get a nice reaction (brown to black) of the skeletal plates.
With a tendency for fusion.
In the United States of America P. hegneri is a secondary immigrant (of Bos taurus).
