690 RECORD OF CURRENT RESEARCHES RELATING TO 



indicative of tlio general good quality of the water than otherwise, as 

 some of them, at least, arc known at home and abroad as the inliabi- 

 tants of deep, clean water only. 



It is curious that hitherto neither Leptodora hynlina nor Hyalo' 

 daphnia Kalhergensis have been found by London microscopists, and 

 yet it cannot be doubted that it must be as plentiful in the neighbour- 

 hood of London as of Birmingham. For tlie former a deep reservoir 

 Kecms to bo essential, the net being dipped G or 7 feet. 



Collection of Living Foraminifera.* — Having been occupied for 

 some years in the study of the rhizopodous fauna of the coasts of 

 France, M. Vandcn Brocck thinks it may be useful to those similarly 

 occupied to publish instructions with a view of facilitating the collec- 

 tion of Foraminifera. The original instructions are very concise and 

 thoy necessarily suffer in the further condensation which we have been 

 obliged to give them. 



In general, the coarse and purely quartzose sand is very poor in 

 Foraminifera, though under certain favourable conditions interesting 

 results may bo obtained, when for instance it contains a sufficient 

 quantity of the debris of shells, sponges, algfc, &c. 



The tide often washes up on the shores of an indented coast a 

 kind of littoral band, at high-water mark, consisting of algfe and light 

 debris of shells, sponges, &c., which generally furnishes good material 

 for the collection of Foraminifera. The debris, if it contains many 

 algse, should be washed in an abundance of water, lightly rubbing it 

 between the hands. To preserve the Foraminifera alive, salt water 

 must be used ; fresh, if the shells only are desired, the latter pre- 

 venting the saline efflorescences which would otherwise cover the shells. 

 The floating residue must be thrown away, carefully preserving the 

 sand deposited in the vessel. Precautions must be taken not to throw 

 away the Foraminifera, which, being lighter than the grains of quartz, 

 float above the sand, under (not on the surface of) the water. The 

 water can also be filtered through coarse muslin and the residue of 

 algfe, &c., rejected. 



The algfe gathered on the beach, or better still, taken from the 

 place of their growtli, give equally good results. It is useful to 

 preserve unwashed a few roots of algfe and flexible polyps, as a great 

 number of living Foraminifera are attached to the leaves and false 

 roots. 



We sometimes find on the coast, amongst the shells and Fora- 

 minifera of recent fauna, others coming from fossil beds, tertiary, 

 cretaceous or otherwise, which, bordering on the sea, are worn away 

 by the action of the waves, or crumble into it from the cliffs which 

 are undermined at high tide. Thus fossil Foraminifera become dis- 

 persed among the recent fauna, and it is therefore very important to 

 take into consideration the neighbourhood in which the sand has been 

 collected. 



In the coarse sand and residues of the shore we generally find 

 nothing but rolled and worn Foraminifera belonging exclusively to 



* ' .Toiirn. fk Micrngr.,' iii. (1879) p. 237. 



