482 



The lecturer then proceeded to describe at some length the 

 more important of the preparations exhibited. The first slide 

 was a general sroup, selected from different parts of the world 

 and from various depths, intended to show the great variety of 

 texture and neatness displayed in the building of the test by the 

 Arenaceous Foraminifera. There was a tolerably complete 

 series, ranging between (1) species in which the particles of 

 building material were simply piled together without much order 

 or definite arrangement, through (2) other species in which the 

 separate particles of building material were visible, but with the 

 joints neatly filled and " pointed " with cement, to (3) species in 

 which the particles used were so large that the bricks were lost 

 in the mortar, so to speak, and a smooth, homogeneous surface 

 resulted. The cement used by Arenaceous Foraminifera is of 

 two kinds — chitinous and ferruginous. The chitinous cement is 

 usually only visible as a film on which the particles are 

 cemented ; but the ferruginous cement, owing to its colour, is 

 one of the most striking features of the whole group. 



In referring to another slide, it was said that the names of 

 the Foraminifera, though cumbrous, are in most cases capable 

 of translation, and often describe the object very neatly. The 

 name of the one then under discussion, Astrorhiza limnicola, 

 meant " the star-shaped root dwelling in the mud." This form 

 exercised practically no selective power, and used hardly any 

 cement. The test was, therefore, very brittle, and was seldom 

 found perfect in cliied material. In referring to another form, 

 Crithionina pisum, Goes. ( = barley-like pea), the speaker said 

 that he thought the name of this little organism was not 

 altogether a happy one. He had puzzled for some time over 

 the propriety of naming a light-grey sphere " barley-like," until 

 he thought of the solution — pearl-barley. It was suggested that 

 the learned Swede who coined the name was most familiar with 

 barley in this form. Specimens of this species are sometimes 

 found which have been perforated by some small boring mollusc. 

 Psammosphaem fasca (= dark sandy sphere), one of the com- 

 monest of the North Sea forms, is, perhaps, the lowest of all as 

 regards selective power. The shell, although always approxi- 

 mately spherical, is very roughly made, sand-grains of all sizes 

 being employed. When no sand is available, as in the deep sea, 

 the animal collects the shells of other Foraminifera, living or 



