194 THK VICTORIAN NATURALIST. [Vol. XXVI. 



Living Foraminifera may be killed by putting them in a mixture 

 of warm saturated solution of corrosive sublimate, 4 parts, and 

 glacial acetic acid, i part. They should then be cleaned in water 

 and placed in picro-carmine for some hours. 



To preserve dredgings, use a 5 per cent, solution of formalin 

 neutralized with a little powdered chalk. 



A valuable reagent for decalcifying the foraminiferal tests for 

 the purpose of observing the protoplasmic body is that 

 known as Perenyi's fluid. It is as follows : — Nitric acid, 10 per 

 cent., 4 vols. ; abs. alcohol, 3 vols. ; chromic acid, 5 per cent., 

 3 vols. 



On the Collection of Fossil Foraminifera.— Tho. calcareous 

 clays afford the better preserved specimens. Sands are nearly 

 always barren, owing to the dissolution of the shells by water 

 percolating through the beds. In washing clays for the extrac- 

 tion of the Foraminifera, it must be borne in mind that this class 

 of rocks, even the most tenacious, will freely disintegrate if first 

 thoroughly dried. Pieces of the size of a walnut, or larger, may 

 be dropped into a vessel of water, and left undisturbed until the 

 whole has broken up into a flocculent mass, when the finer 

 argillaceous and amorphous constituents may be separated by 

 washing. The cleaning process is facilitated by pouring off most 

 of the water and rapidly whirling or shaking the vessel until the 

 fossil organisms are freed by friction from the obscuring clay 

 particles. Example : —The Tertiary clays of Balcombe's Bay. 



With limestones a different course of treatment is necessary. 

 The specimens selected should be as friable as possible. They 

 should be placed in a strong vessel, or, preferably, in a porcelain 

 mortar, with enough water to just cover the fragments, and then 

 gently pounded by as slight a pressure as will break down the 

 material. Example : — The Tertiary limestone of the Filter 

 Quarry at Batesford. In England this disintegration of refrac- 

 tory fossiliferous rocks is done by putting out the specimens 

 during a sharp frost, and, although in this country such 

 conditions would only be obtainable in the Australian Alps, yet 

 the method could be resorted to by artificial means of freezing. 

 In some exceptional cases even hard limestones will allow the 

 foraminiferal tests to be separated by the coercive measures 

 described above. The disintegrated rubble may then be washed, 

 dried, and sifted, preparatory to sorting. 



Sorting Foraminiferal Residues. — To render the selection of 

 specimens easy, it is advisable to sift the dried material into 

 grades of varying coarseness. A set of sieves will be found 

 useful, having 30, 60, and 90 meshes to the linear inch. 

 Advantage of the shape of the foraminiferal tests may be taken 

 from the tendency of the more globular or cylindrical forms to roll 

 on an inclined plane. The sorting of the first grade of siftings 

 may be easily done with a lens, but the finer material will require 



