436 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



in this locality, as well as in those of Lituola and other Arenaceous types 

 inhabiting the Cold area, where the bottom is formed by sand and small 

 stones alone. 



62. It is not a little curious that one of the new types* discovered last 

 year in the 650 fathoms' dredging (' Lightning' Report, § 19), which was 

 made in a part of the Warm area far removed from the borders of 

 the Cold, was now found to occur here also, but with a remarkable 

 difference in the structure of its " test." Its shape is fusiform, gene- 

 rally somewhat curved, not unlike a § ; and it has only one undivided 

 cavity, with a tubiform aperture at each end. Now in the true Cre- 

 taceous area, where sand-grains are scarce, but sponge-spicules abound, 

 this Rhizopod constructs its "test" almost entirely of sponge-spicules, 

 laid with most extraordinary regularity, a sand-grain being interposed 

 here and there to fill up a vacuity left by the oblique crossing of the 

 spicules. But in the Holtenia-vxoxmdi, where sand is abundant, " tests" 

 of precisely the same general form and proportions are built up almost 

 entirely of sand-grains cemented together ; sponge-spicules, however, being 

 invariably used to form the tubiform mouths, and the mouth thus formed 

 being sometimes prolonged like a proboscis. — It is difficult to conceive 

 how creatures which seem nothing more than particles of animated jelly, 

 without " organs" of any kind, can exert so remarkable a power of selec- 

 tion and construction as is shown in the "tests" of some of these Arena- 

 ceous Foraminifera. There are none which are more symmetrically con- 

 structed than the triradiate Rhabdarnmina ; each of its three very slender 

 arms, which diverge at equal angles, being a cylindrical tube, built up of 

 sand-grains of very uniform size, united by a firm cement which contains 

 a considerable proportion of Phosphate of Iron. This tube is beauti- 

 fully smoothed off internally ; and it is no rougher externally, in propor- 

 tion to its size, than any wall would be that is built of rough-hewn 

 stones arranged by the hands of a most dexterous mason. The only 

 structure with which we are acquainted that is at all comparable to it in 

 workmanship is the sandy tube of the Pectinaria, one of the Tubicolar 

 Annelids, a creature comparatively high in the scale of organization. 



63. It was here that we employed for the first time an addition to our 

 Dredging apparatus devised by Capt. Calver, who, having noticed that 

 animals frequently came up attached to the part of the dredge-rope that had 

 lain on the ground, or to the net of the dredge itself, justly reasoned that 

 if the Sea-bottom were swept with hempen brushes, they would probably 

 bring up many creatures that might escape the scrajnnr/ of the dredge. 

 These brushes were made of bundles of rope-yarn teazed out into their sepa- 

 rate threads, and tied together at the top, so as closely to resemble the 



* This typo was described by Dr. Carpenter in a Memoir presented to the Koyal 

 Society, June 17th, " On the Ehizopodal Fauna of the Deep Sea," as a form of the 

 Proteonina of Prof. Williamson. He has subsequently been led to doubt, however, 

 whether that designation can be properly applied to it. 



