﻿Cryptozoon and otJier Ancient Fossils. 211 



The spicules connected witli them, if organic, would seem 

 to have been set in the membrane, and to have been 

 corneous rather than silicious. I have, however, no 

 absolute certainty that tliese apparent spicules may not 

 be rather the effect of prismatic crystals of calcareous 

 spar penetrating a soft animal matter and impressing on 

 it their own forms. If the spicules are really organic, 

 the structure must be of the nature of a sponge. If 

 otherwise, it must have consisted of double membranous 

 layers enclosing between them a softer organic matter, 

 and sufficiently firm to retain their form till filled in with 

 calcareous fragments. Unless the structure was of vege- 

 table origin, which I do not think likely, it was probably 

 a Protozoan of some kind. In either case it is different 

 from any fossil hitherto found in the Lower Carboniferous 

 limestones of Nova Scotia." It is introduced here merely 

 as a possible successor of Cryptozoon. 



I think we are justified in holding that the fossils of 

 the type of Gryptozoon constitute a type differing from 

 that of the ordinary stromatoporae, and probably inferior 

 to them in organization. At one time I supposed that 

 the Ordovician forms contained in the genus Stromata- 

 cerium of Hall might be a connecting link, and in some 

 respects of general arrangement they certainly conform 

 to Cryptozoon ; but in so far as I have been able to 

 examine them microscopically, their affinities seem to be 

 witli the typical Stromatoporae. Still, there remains even 

 in my own collection a large amount of material referred 

 to Stromatocerium which has not not yet been sliced and 

 examined. 



Of modern forms, that which seems to approach nearest 

 to Cryptozoon is the remarkable organism dredged by 

 Alexander Agassiz in the Pacific,^ and which has been 

 described by Goes as an arenaceous foraminifer, under the 



1 Lat. 107' N. Long. 8° 4' W., 1,740 fathoms.- "Albatross" Expedition.. 



