Nature of the so-called " Bathybius." 329 



presently to be described, some cells, however, attain a much 

 larger size"*. 



" The coccoliths (to which term I would restrict, the minute 

 bodies described by Prof. Huxley) are of oblong shape, con- 

 cave on their internal aspect, namely that on which they are 

 attached to the surface of the coccosphere-cells, and convex 

 externally ; in short, they are spoon-shaped, only with a much 

 less marked convexity and concavity. In some specimens a 

 single aperture, only, occurs at the central portion. In others 

 the aperture appears to be double ; or, rather, there are two 

 perforations, placed side by side, in the direction of the long 

 axis of the body, and separated from each other by an ex- 

 tremely delicate transverse band ; whilst the external marginal 

 surface, which thus constitutes a quoit-like but oblong ring 

 round the central perforated portion, is striated in a radiate 

 manner. When the two perforations are present the little 

 mass closely resembles a miniature plate of Synapta. The 

 coccoliths, like the spheres upon which they rest, are trans- 

 parent and devoid of colour. Their mode of attachment is not 

 distinguishable, owing to their extreme minuteness. They 

 appear, however, to be simply placed in contact with the sur- 

 face of the coccosphere-wall, and to be retained in position by 

 the delicate gelatinous layer in which the entire organism is 

 invested. We may thus account for the seeming facility with 

 which the coccoliths are detached, and the vast numbers of 

 free coccoliths which crowd many of the deposits "f. 



Apart, therefore, from the primary question whether " Batliy- 

 bius " does or does not possess the characters attributed to it — 

 characters which, if existent, must have wholly revolutionized 

 our views regarding both the biological and geological rela- 

 tions of the sea-bed — it must be obvious that the true relation 

 of the " coccoliths " to the coccospheres, and the equally sig- 

 nificant facts (pointed out by me some years previously), first, 

 that the coccospheres are normally free-floating organisms, 

 inhabiting the surface-waters of the open ocean J, where there 

 exists no protoplasmic matrix for them to be imbedded in } 



* In a collection of microscopic slides illustrating the nature of the 

 North-Atlantic deposits, which was presented by me to the Microscopical 

 Society in 1867, there are numerous examples both of Textularian and 

 Rotalian shells, the outside of the chambers of which are studded with 

 coccoliths as here described. 



t "On some novel Phases of Organic Life at great Depths in the Sea," 

 by G. C. Wallicb, M.D. &c. (Annals and Magazine of Natural History, 

 July 1861, p. 52). 



J See paper " On the Structure and Affinities of the Polycystina," by 

 0. C. Wallich, M.D. &c. (Quarterly Journal of Microscopical Science 

 for July 1865, footnote). 



