264. Kerona Haustrum.
K. orbiculata, corniculis mediis, antice membranacea ciliata, postice setosa. Orbicular kerona, with the horns in the middle, the fore-part membranaceous and ciliated, and several bristles at the hinder-part.
265. Kerona Haustellum.
Differs from the preceding only in having the hinder-part without any bristles.
266. Kerona Patella.
K. univalvis, antice emarginata corniculata, postice setis flexilibus pendulis. [Plate XXVII.] Fig. 22 and 23. Kerona with a univalved shell, orbicular, crystalline; the fore-part somewhat notched; the fleshy body lies in the middle of the shell; above and below are hairs or horns of different lengths jutting out beyond the shell, and acting instead of feet and oars, some of which are bent; the superior ones constitute a double transverse row. a, the fore-part; b, the horns; d, a lunated figure in the shell; c, a pulpous body; f, bristles at the hinder-part.
267. Kerona Vannus.
K. ovalis subdepressa, margine altero flexo, opposito ciliato, corniculis anticis, setisque posticis. Oval and rather flat kerona, with one edge bent, the opposite one ciliated, the front furnished with horns, and the hind-part with bristles.
268. Kerona Pullaster.
K. ovata, antice sinuata, fronte crestata, basi crinita. [Plate XXVII.] Fig. 24 and 25. Oval, the fore-part sinuated, a crest on the front, the base hairy.