Drawing made by Cash, in Cash and Hopkinson, 1905:
Diagnosis of genus Biomyxa:
Body consisting of finely-granular protoplasm, semi-fluid and colorIess; initial form sub-spherical; the body capable of much elongation, and branching out into a network of fine anastomosing filaments, which are generally massed at the extremities, but may also emanate from different points of the surface.
From Gymnophrys this genus is distinguished by the habit of the body to elongate, and of the finer pseudopodia to become massed at the extremities, whilst from Penardia the pale colorless endoplasm clearly marks it off. From the latter it is further separated by general habit (being purely a chlorophyll feeder) and by its more dilatory movements.
Diagnosis of Biomyxa vagans:
Body when contracted roundish or roughly ovoid at other times mobile, throwing out branching and inosculating pseudopodia which form ultimately an intricate network, “often,” to quote Leidy’s description, “expanding into perforated patches” Protoplasmic substance pale, finely granular, rarely containing chlorophyllous matter; but numerous minute vesicles and oil-like molecules are usually present, the former occurring near the margin of the body and along the pseudopodal extensions. The nuclear structure is undetermined. A circulation of minute granules is perceptible along the filamentous pseudopodia.
Dimensions: extremely variable.
In swampy ground, amongst Sphagnum; also in tufts of moss on moist rocks. Dunham, Cheshire
Isle of Man.
The pale colourless protoplasm and its finely and uniformly granular structure are distinctive of this organism, separating it at once from Leptophrys, of which no British examples, so far as we know, have been found. The Isle of Man examples of Biomyxa, which occurred in tufts of Barbula growing on rocks near the coast, at Perwick Bay, agreed most of closely with Leidy’s descriptions and figures. A study of Leidy’s figures on Plates xlvii and xlviii of Freshw. Rhiz. N. Amer.,’ leads to a suspicion that he may have included Gymnophrys with this genus.
From: Cash and Hopkinson, 1905