176 



Postscript, February, 1849. 



Since the preceding memoir was placed in the hands of the Secretary of the 

 Microscopical Society, I have had the opportunity of perusing M. D'Orhigny's new 

 work 'Sur les Foraminiferes Fossiles du Bassin Tertiare de Vienne.' In the early 

 pages of this volume he emhodies the more recent views that have been promulgated 

 respecting the nature of the Foraminifera, but without any acknowledgement of the 

 labours of those whose discoveries have led to the abandonment of his original idea 

 that the Foraminifera were cephalopodous animals. He has arrived at several con- 

 clusions, which are in accordance with my own results. He holds that they are not 

 aggregate creatures : he recognizes the power of the pseudopodia to secrete the calca- 

 reous covering, — the universally rounded form of the primordial segment of the soft 

 animal, — the inability of a segment once formed to increase its dimensions, — the ab- 

 sence of evidence as to the existence of a special intestinal canal, or organs of repro- 

 duction, and the power of the pseudopodia to absorb nourishment: all these being 

 conclusions to which I have arrived in the preceding memoir, from independent evi- 

 dence. As to their zoological position we differ considerably. He concludes that they 

 ought to be arranged as an independent class, between the Polypifera and the 

 Echinodermata; an opinion with which, from the reasons enumerated in the preceding 

 pages, I cannot concur. His definition of the generic characters of Polystomella, is 

 still the same as that which I have quoted in page 162, scarcely a letter being altered, 

 and consequently, as inapplicable as its predecessors to the real types of the genus. 



