Coccoliths And Coccospheres, names given, the former by Prof. Huxley, the latter by Dr. Wallich, to minute rounded bodies adherent to the gelatinous submarine protoplasm to which Prof. Huxley gave the name of bathybius. (See Bathybius.) The latter are larger and more complex in structure than the former. The coceoliths he subdivides into discoliths and cyatho-liths. He describes the discoliths as oval discoi-dal bodies with a thick, strongly refracting rim, and a thinner central portion, the greater part of which is occupied by a slightly opaque cloud patch, corresponding to the inner edge of the rim, from which it is separated by a transparent zone; in general, they are slightly convex on one side and correspondingly concave on the other, and the rim is raised on the more convex side; they are about 1/5000 of an inch in their longest diameter. The cyatho-liths are like minute shirt studs, varying in size from 1/6000 to 1/8000 of an inch. Cocco-spheres are described as of two types, one compact, the other loose in texture; the largest of the former type being about 1/1300, and those of the loose type 1/760 of an inch in diameter; they seem to be made up of bodies resembling cyatholiths; in fact, Dr. Wallich believes that the coccospheres are the parents of the cocco-liths; both, without doubt, are the calcareous hard parts belonging to bathybius.

These bodies have been found fossil in the chalk, showing the close resemblance of the conditions under which the chalk beds were formed to those existing at the bottom of the present Atlantic ocean.

Coccoliths, magnified.

Coccoliths, magnified.