Globigerina a microscopic protozoan animal, of the foraminiferous order of the class of rhizopods. The body is composed of simple sarcode or protoplasmic matter, enclosed in a shell pierced by numerous minute openings, through which a film of the animal substance is exuded, capable of throwing out small thread-like processes, or pseudopodia. The animals increase by budding, each sarcode mass being enveloped in its calcareous shell, but connected irregularly with all the rest of the colony; there is no definite shape, the mass being compared by Huxley to that of a badly grown raspberry. Recent deep-sea dredgings (in the Gulf stream at a depth of 3,100 ft., near the Faroe islands at a depth of 3,900 ft., off Cape Farewell, Greenland, at 7,560 ft., and between the Azores and Newfoundland at 10,000 ft., and in the north Atlantic at still greater depths in the track of the Atlantic cable) have brought up the shells of living globigerina3 from the calcareous ooze of the ocean bottom. In the compound protoplasmic animal to which the name of bathybius has been given, are found globigcrina3, with coccoliths and coccospheres; the ancient chalk deposits are made up almost entirely, in many specimens, of remains of the three last named animals, the same as those now living on the bottom of the ocean; the great central plain of the North Atlantic, 1,000 m. wide and many hundreds in length, nearly level, is covered with a chalky mud containing innumerable globigerinae with their attendant coccoliths and coccospheres, and the deeper the sea the larger are these animals.
They doubtless constitute the food of the star fishes, which also have been dredged from these great depths. There is no reason to think that the habits and the habitats of the ancient chalk animals were different from those of the living globigerinae; hence we may conclude that the chalk formation, constituting a large part of southern Great Britain and central and southern Europe, often 1,000 ft. thick, is the dried and elevated mud of an ancient deep sea. From the fact that this present deep-sea fauna is apparently identical with that of the ancient chalk, there seems to be some ground for the statement that the cretaceous period at the bottom of the sea has extended to the present time. For very interesting suggestions concerning the geology and antiquity involved in the study of these animals, the reader is referred to a lecture by Prof. Huxley "On a Piece of Chalk," delivered in 1868, and published in "Lay Sermons and Addresses" (New York, 1871). (See Bathybius, Cocco-liths, and Foraminifera.)