[Footnote 8:  “Preliminary Notes on the Nature of the Sea-bottom procured by the soundings of H.M.S. Challenger during her cruise in the Southern Seas, in the early part of the year 1874.”—­Proceedings of the Royal Society, Nov. 26, 1874.]

“Mr. Murray has combined with a careful examination of the soundings a constant use of the tow-net, usually at the surface, but also at depths of from ten to one hundred fathoms; and he finds the closest relation to exist between the surface fauna of any particular locality and the deposit which is taking place at the bottom.  In all seas, from the equator to the polar ice, the tow-net contains Globigerinoe.  They are more abundant and of a larger size in warmer seas; several varieties, attaining a large size and presenting marked varietal characters, are found in the intertropical area of the Atlantic.  In the latitude of Kerguelen they are less numerous and smaller, while further south they are still more dwarfed, and only one variety, the typical Globigerina bulloides, is represented.  The living Globigerinoe from the tow-net are singularly different in appearance from the dead shells we find at the bottom.  The shell is clear and transparent, and each of the pores which penetrate it is surrounded by a raised crest, the crest round adjacent pores coalescing into a roughly hexagonal network, so that the pores appear to lie at the bottom of a hexagonal pit.  At each angle of this hexagon the crest gives off a delicate flexible calcareous spine, which is sometimes four or five times the diameter of the shell in length.  The spines radiate symmetrically from the direction of the centre of each chamber of the shell, and the sheaves of long transparent needles crossing one another in different directions have a very beautiful effect.  The smaller inner chambers of the shell are entirely filled with an orange-yellow granular sarcode; and the large terminal chamber usually contains only a small irregular mass, or two or three small masses run together, of the same yellow sarcode stuck against one side, the remainder of the chamber being empty.  No definite arrangement and no approach to structure was observed in the sarcode, and no differentiation, with the exception of round bright-yellow oil-globules, very much like those found in some of the radiolarians, which are scattered, apparently irregularly, in the sarcode.  We never have been able to detect, in any of the large number of Globigerinoe which we have examined, the least trace of pseudopodia, or any extension, in any form, of the sarcode beyond the shell.

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“In specimens taken with the tow-net the spines are very usually absent; but that is probably on account of their extreme tenuity; they are broken off by the slightest touch.  In fresh examples from the surface, the dots indicating the origin of the lost spines may almost always be made out with a high power.  There are never spines on the Globigerinoe from the bottom, even in the shallowest water.”