280 Mr. Parkinson on Elppiuhes. 



satisfaisante." (Description de plusieurs nouvelles especes d'ortho- 

 ceratites, &c. p. 15.) 



A due attention however to their peculiar organization would, it 

 may be supposed, have prevented the multilocular shells from having 

 been considered as pelagian shells. But M. Denys de Montfort, 

 with most of the French oryctologists, is disposed to believe that all 

 those shells which are known to us only in a fossil state, and which 

 have therefore been supposed to belong to animals which are now 

 extinct, do actually belong to animals which constantly inhabit the 

 bottom of the sea, never rising to the surface, or appearing on the 

 shores. Thus the orthoceratites, ammonites, and belemnites, not- 

 withstanding their possessing different modifications of that organi- 

 zation by which the nautilus is enabled to raise itself to the surface of 

 the water, are all considered as petrified pelagian shells, whose recent 

 analogues have not yet been brought to view. Thus speaking of 

 the simplegade couhuvrce ( simple gades coluhratus )^ a fossil shell 

 hitherto considered as an ammonite, but which this author has 

 thought right to place under a distinct genus, he says, " II est tres 

 probable que les simplcgades, comme beaucoup d'autres mollusques 

 pelagiens, viveni dans le fond des hauts mers, et qu'une cause 

 physique quelconque ne leur permet point de paroitre a la surface des 

 eaux." (Conchologie Systematique, ^c. p. 84.) 



Having already opposed this opinion in a general way, in my 

 Examination of the organic remains of a former ivorld; and having 

 shown that in all the known multilocular fossil shells such an orga- 

 nization existed as was well calculated to enable the animals to raise 

 themselves occasionally to the surface of the water, I shall here 

 endeavour to determine how far the specimens presented to the 

 Society will show, that this property was possessed by the hippurites. 



On examining those parts of this fossil, which have been hitherto 



