ON THE LIFE-HISTORY OF THE FORAMINIFERA. 175 



X. Questions regarding the Life-History of the Foramini- 

 fera, suggested by examinations of their dead shells. By 

 Thomas Alcock, M.D. 



[Eead before the Microscopical Section, October i6th, 1865.] 



The specimens of Foraminifera which have suggested the 

 following remarks were obtained from an extensive deposit 

 of calcareous sand on the shore of Dogs Bay, near Bound- 

 stone. They are found in excellent condition, most of them 

 being not at all worn and rarely broken ; and their abun- 

 dance may be understood from the fact that folly three- 

 fourths of the whole mass of the sand consists of their shells. 

 Though it may be generally true that dredging is the only 

 satisfactory way of getting good material for examination, a 

 deposit like this certainly forms an exception, and deserves 

 thorough investigation; already it has yielded a greater 

 number of distinct forms than are described by Prof. Wil- 

 liamson from the whole extent of the British Seas ; seventy- 

 four of them agree with forms figured in his ' Becent Fora- 

 minifera of Great Britain,^ but the remainder are either 

 very decided and remarkable varieties, or they are per- 

 fectly distinct from any there described. 



This sand was first brought under my notice four years 

 ago by Mr. Thomas Glover, who observing the great number 

 of small shells of MoUusca it contains, brought away a 

 supply of the material with the intention of picking them 

 out at leisure, and gave some of it to me for the same pur- 

 pose. After having worked for some time at these small 

 Mollusca, which are distinguishable without the aid of a 

 microscope, and having obtained in this way many beau- 

 tiful and interesting species, I separated the finer from the 

 coarser parts by means of a sieve, and gave the finer ma- 

 terial a special examination. The extraordinary richness 



