Birgea Harring & Myers, 1922

[ref. ID; 1663]
Foot slender and sharply set off from the wide body. Trophi aberrant, with a pair of pseudunci. Body length 240-275 um long. Single rare littoral species. (ref. ID; 1663)

[ref. ID; 1923]
Body barrel-shaped, with very narrow cylindric foot set off from body. Stomach with zoochlorellae, no gastric glands. (ref. ID; 1923)

[ref. ID; 3245]
Notommatid rotifers with short, broad, illoricate, anteriorly truncate body; the head is short and very broad, separated from the abdomen by a slight constriction; the abdomen is ovate and ends posteriorly in a short, broad tail; the foot is long, very slender and three-jointed; the toes are fairly long and lanceolate. The corona is frontal with a circumapical band of short cilia, interrupted dorsally, and two lateral, auricle-like areas with long cilia adapted to propulsion; the buccal field is evenly ciliated and the mouth is near the ventral edge. The mastax is very aberrant; the trophi, which normally seize and subdivide the food, are virtually atrophied and their functions transferred to a pair of hooked "pseudunci", probably a highly specialized form of the epipharynx; no gastric glands are present, but the walls of the stomach are produced into a number of gastric caeca and contain symbiotic zoochlorellae. No retrocerebral organ is present; the ganglion is small and the eyespot at its posterior margin. (ref. ID; 3245)