I^OTES OK RBtlCULAHIAN RHIZOPODA. 4§ 



Genus— TRVRAMUm A, nov. 



(Ovp'ig, a cell ; afxfioq, sand) . 



General characters. — Test free or adherent; either con- 

 sisting of a single rounded chamber, sometimes enveloping 

 a similar one of smaller size, or of two or more (apparently) 

 independent chambers adhering to each other. Texture 

 thin ; arenaceous or chitino-arenaceous. Surface beset with 

 numerous, perforate, nipple-shaped protuberances. 



ThURAMMINA PAPILLATA, 71. sp. PI. V, figs. 4 — 8). 



Oth\x\\n& Lituola, Carpenter, 1S75, ' The Microscope and its Revelations,' 

 Fifth Ed., p. 533, fig. 273, c/. h. 



Characters. — Test free or adherent ; usually consisting of a 

 single spheroidal chamber, with or without an elongated neck ; 

 occasionally of two or more of such chambers mutually 

 adherent. Surface studded with irregularly disposed per- 

 forate papillae. Colour brown ; shell-wall, very thin, com- 

 posed of light-coloured sand-grains fitted together accurately 

 with reddish-brown cement. Diameter of the chambers -^^ 

 inch (0'5 millim.), more or less. 



Dr. Carpenter (loc. cit.) gives a partial description of this 

 type, founded apparently on an insufficient number and 

 variety of specimens, to yield a clear sense of its morpholo- 

 gical range. The shell represented by fig. 4 (PI. V) gives 

 H fair idea of its usual contour and condition, but it frequently 

 happens that the neck is wanting, and in such cases there is 

 no general pseudopodial aperture distinct from the orifices of 

 the papillae. Occasionally the test is adherent either to a 

 piece of shell, as in fig. 5, or to some other foreign body, and 

 then the shape is altered to meet its changed relations. 

 Sometimes two or three chambers are found adherent to each 

 other, as in fig. 8, but in such cases the individual segments 

 appear to retain their independence, and not to assume with 

 each other a corporate existence as a single polythalamous 

 organism. That is to say, the polythalamous condition depends 

 on the adhesion of spheres by their contiguous surfaces rather 

 than on the segmentation of sarcode and the formation of 

 connecting stolons with corresponding shelly investment. 

 Occasionally, though rarely, on breaking the test a second 

 smaller chamber with papillate projections is found in the 

 interior ; such an example is seen in fig. 6, and a primordial 

 chamber of this sort from another shell is shown in fig. 7. 

 The hiinute structure of the shell-wall is very beautiful. 



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