46 HENRY B. BRADY. 



It is formed of angular sand-grains accurately fitted to each 

 other and held together with a dark reddish-brown cement. 



The number and degree of prominence of the nipple-like 

 projections vary very much. In some specimens they are 

 very numerous and striking, and they are often arranged in 

 a sort of linear order; in others they are much less conspicuous, 

 and are irregularly distributed. They are probably all per- 

 forated, but the apertures are often very obscure. 



The distribution of Thuranimina papiUata is world-wide. 

 The " Challenger " collections furnish specimens from both 

 the North and South Atlantic and the North and South 

 Pacific. Of ten localities in which I have record of its occur- 

 rence, five are from depths of more than 2000 fathoms, and 

 only three of them less than 1000, the shallowest of all being 

 350 fathoms, so that it may be regarded as an essentially 

 deep-water type. 



Thurammina albicans, n. sp. 



Characters. — Test free, monothalamous, nearly spherical, 

 with few (4 or 6) mammillate orifices, equidistant and regu- 

 larly disposed. Texture very finely arenaceous, colour white. 

 Diameter -Hro inch (0-25 millim.). 



A few specimens of a very minute organism, apparently 

 allied to the foregoing species, have been found in several 

 of the *' Challenger '' dredgings. The test is much 

 smaller than that of TJiurammina papillata, the shell-wall 

 relatively thicker and composed of finer materials, and the 

 little mammillate protuberances, instead of being numerous 

 and distributed irregularly over the surface, are few in 

 number and placed symmetrically. The figures of this form 

 have unfortunately had to be omitted for want of space. 



Single specimens have been met with in many samples of 

 deep-sea material. Perhaps the best series is from 1900 

 fathoms, off" the coast of South America, in about the latitude 

 of Buenos Ayres. 



Thurammina compressa, 7i.sp. PI. V, fig. 9. 

 Characters, — Test free, monothalamous, compressed; with 

 numerous perforate, mammillate protuberances arranged 

 irregularly on the periphery. Walls thin, chitino-arenaceous ; 

 colour dark-brown. Diameter, -V inch (0*5 millim.). 



This is another form, rarely met witli, apparently nearly 

 related to Thurammina papillata. Its chief distinction rests 

 on its membranous, only slightly arenaceous, shell-texture, 

 and its compressed lenticular contour. It is just possible that 

 the latter character may be in a measure accidental, and be 



