26 FORAMINIFERA. 



Foraminifera, Ostracoda, and other microzoa. The surface of 

 muddy, oozy sea-shores is mostly pecuharly rich in these delicate 

 shells. They also occur, in some instances plentifully, in sea- 

 soundings at all depths ; in the mud deposited at the mouth of all 

 tidal rivers ; in the mud and marl found in the " raised beaches " 

 (which are far from uncommon), though sometimes many feet 

 above the present sea-level, and, it may be, miles away from the 

 sea. What is known as " Estuarine Clay " and " Boulder Clay " 

 is often richly stored with them. 



In all the above, the Foraminifera present pretty nearly the 

 same appearance, as a rule, and may, for the purposes of this 

 paper, be regarded as "recent." 



Fossil Foraminifera are abundant in almost every clay found 

 in the Lias, in the London Clay, in* the Suffolk Crag, in the 

 Carboniferous Limestones and Shales, and in the Chalk, being 

 especially well preserved in the soft powder found in the interior 

 of the large flint nodules called " Paramoudras," of which I shall 

 speak in a future paper.* 



The methods adopted for separating the Foraminifera from 

 the materials in which they occur vary according to the character 

 of that material, the " recent " requiring very different treatment 

 to the "fossil." All recent Foraminifera being full of air when 

 dry, will (except the very large ones) float in water ; but all fossil 

 Foraminifera, being generally solid casts more than simple shells, 

 sink to the bottom. By availing ourselves of this power of float- 

 ing, we secure with very little trouble a ready means of separating 

 the shells of the Foraminifera, Ostracoda, etc., from the sand with 

 which they are generally intermixed, and thus reduce what would 

 otherwise be a most tedious and difficult operation, involving an 

 enormous sacrifice of time, into one which is at once simple, 

 easy, rapid, and satisfactory, and which is performed somewhat as 

 follows : — 



To obtain recent Foraminifera from sa;id, such as shore- 

 gatherings, dredgings, etc. 



If wet and fresh, stir up in plenty of cold, fresh water, in 

 order to remove as much of the salt as possible, and if time is 

 no object, allow to stand all night, so as to soak out all the salt. 

 Skim off everything that floats, picking out bits of weed and such- 

 like, and examine the same for any forms which may be adhering 

 to them. This washing may be most easily done on a very fine 

 sieve, which can be put into a large pan and kept under a tap of 



* Paramoudra is the name given to the large, irregularly cylindrical, but really 

 amorphous masses of flint, large as a chimney-pot, often found in chalk, two, 

 three, four, or more, one over the other, something like a chimney-stack ! What 

 these were is not yet known. 



