XXVI. On the Rhizopodal Fauna of the Deep Sea

The Author commences by referring to the knowledge of the Rhizopodal Fauna of the Deep Sea which has been gradually acquired by the examination of specimens of the bottom brought up by the Sounding-apparatus; and states that whilst this method of investigation has made known the vast extent and diffusion of Foramimferal life at great depths,-especially in the case of Globigerina-mud, which has been proved to cover a large part of the bottom of the North Atlantic Ocean,—it has not added any new Generic types to those discoverable in comparatively shallow waters. With the exception of a few forms, which, like find their most congenial home, and attain their greatest development, at great depths, the general rule has seemed to be that Foramimfera are progressively dwarfed in proportion to increase of depth, as they are y a change from a warmer to a colder climate; those which are brought up from great depths in the Equatorial region bearing a much stronger resemblance to those of the colder-temperate, or even of the Arctic seas, than to the littoral forms of their own region.