550 Transactions of the Society. , 



ment, but no specimens attached to sand grains have been found. 

 The projecting flanges when perfect have the rounded swollen 

 appearance of wet mortar squeezed out between two rows of bricks in 

 building. 



Thurammina papillata var. cariosa Flint. 



Type, T. cariosa Flint (Ref. 30, pi. xxii, fig. 2). 

 Plate XXIX, figs. 1-11. 



Flint's variety cariosa is abundant and typical in " Goldseeker" 

 material, and presents a number of interesting features, which are 

 more readily observed in this form than in its associates, owing to 

 the comparative ease with which it may be sectioned, the spongy 

 test being soft as compared with the other types. We have already 

 referred to the occurrence of young individuals inside the parent. 



The "Goldseeker" series of cariosa present little variation from 

 Mint's type as described and figured, and the variety is not subject 

 to the wild-growing habits of papillata. Beyond tlie occurrence of 

 compressed individuals, and of double, triple and quadruple speci- 

 mens, practically no variation exists, except in the extent of the 

 development of the secondary reticulated shell-growth which coats 

 the mature test. 



Of the early stages of cariosa after the release of the chitinous 

 3mbryos we have no knowledge. The variety recognizable as such 

 makes its first appearance in all the numerous gatherings, in which 

 we find it as an adult shell of greyish, or sometimes pinkish-grey, 

 colour, constructed of the finest mud or sand, and with a matt 

 surface studded with numerous inconspicuous and almost im- 

 perforate papillae, between which the surface of the sphere is 

 covered with fine reticulated markings (PI. XXIX, fig. 1). At this 

 stage it is practically indistinguishable from some modifications of 

 the sphere type, except for the faint reticulations. It then begins 

 to coat the surface of the sphere with a layer of spongy sliell matter 

 ( z= "cavernous" layer of Flint), concealing the papillae and giving 

 the surface of the sphere a dirty and eroded appearance (PL XXIX, 

 figs. 2, 3). When two or more individuals are in association this 

 spongy matter often fills up the whole of the intervening gap 

 between the spheres. The size of the cavities in the " cavernous 

 layer " is very variable (PI. XXIX, figs. 4, 5), and on occasions is so 

 large as to resemble a bath-sponge under a 1-in. ol>jective. The 

 interior of the sphere is smooth and lined with a chitinous film, 

 generally pink to brown in colour. We figure a series of specimens. 



Thura/nvmina papillata var. albicans Brady. 



Type, T. albicans Brady (Ref. 12, pi. xxxvii, figs. 2-7). 



Plate XXIX, figs. 12-15. 



Of the recorded species of Thurammina only albicans Brady 

 remains. This occurs not infrequently in some of the deeper 



