368. Brachionus Dentatus.
B. bivalvis, testa arcuata, apice et basi utrinque dentata, cauda spina duplici. Bivalved brachionus, with an arched shell; the apex and the base are both toothed, and the tail formed of two spines.
369. Brachionus Mucronatus.
B. bivalvis, subquadrata, apice et basi utrinque mucronata, cauda spina duplici. Bivalved, somewhat of a square form; the base and apex pointed; the tail consisting of two spines.
370. Brachionus Uncinatus.
B. bivalvis, testa ovali, apice integra, basi mucronata, cauda rugosa biseta. [Plate XXVII.] Fig. 55. Bivalved brachionus, with an oval shell, the apex even, the base pointed, two thick bristles for the tail.
This is one of the smallest bivalved animalcula, muscular, the apex and anterior part round, the hinder part straight, terminating in a point, furnished with a hook on the fore-part, a small rotatory organ, a long tail composed of joints, and divided at the end into two bristles. It can open its shell both at the fore and hind-part. a, the shell when close; c, the posterior point; d, the animalculum; h, the tail; i, the bristles.
371. Brachionus Cirratus.
B. capsularis, testa apice producta, basi curti bicorni, cauda biseta. Larger than the preceding, ventricose, somewhat pellucid, the head conical, with a bundle of hairs on both sides; it has likewise a rotatory organ.