Archceozoon. The objects obtained by Dr. G. F. Matthew 

 from the Pre-Cambrian limestones of St. John, New Bruns- 

 wick, Canada, and named by him Archceozoon acadiense,^ ap- 

 pear to be the same, or very similar, organism as Hall's Crypto- 

 zoon, the chief difference being that while in Gryptozoon the 

 laminae are concave to the direction of growth, in Archceozoon 

 they are convex. This, however, may be of slight morpho- 

 logical importance, and may indicate a difference of not more 

 than specific value, if even it be that. 



The zoological position of this ancient organism is ill- 

 defined and cannot, at present, be satisfactorily determined. 

 In the first instance, and for some time after their discovery, 

 they were regarded as Stromatoporoid in their affinities with 

 probable relationships with the Hydrozoa. Later, when the 

 microscopical structure was investigated, Dawson was led to 

 believe that they were more nearly related to the Rhizopodal 

 Protozoa. He says : "If we endeavour in imagination to 

 restore these curious organisms, the task is a very difficult one. 

 They, no doubt, grew on the sea-bottom, and must have had 

 great powers of assimilation and increase in bulk. Still, it 

 must be borne in mind that they were largely made up of 

 inorganic particles collected from the mud and fine sand in 

 process of deposition. The amount of actual organic matter 

 in the hard parts, even of large specimens, is not very great, 

 and the soft living material, if they were animal, must have 

 been confined to the canals and to the exterior surfaces. 



"As the only marine animals known to accumulate foreign 

 matter in this manner are the Protozoa of the Rhizopod type, 

 one naturally turns to them for analogies, and perhaps species 

 of the genus Loftusia most nearly resemble them in general 

 arrangement." ( 7 ) 



When Dawson gave these descriptions the relatively large 

 organisms, Loftusia and Parkeria, as well as the much-dis- 

 cussed Eozoon, were regarded as Foraminifera. Since then, 

 the first two mentioned have been classed with the Hydrozoa, 

 and the third has been relegated to the inorganic world. 



Gryptozoon is of gigantic size, even when compared with 

 the largest of all known Foraminifera, and its internal struc- 

 ture is by no means conclusive of a relationship to these or 

 any other section of the Protozoa. The large proportion which 

 the mineral constituents bear to the whole structure is sug- 

 gestive of an animal rather than a vegetable origin, although 



(6) G. F. Matthew, Presid. Add. Nat. His. Soc. of New Bruns- 

 wick, Bull, ix., p. 32 (1891) also, same author, Note on Archceozoon, 

 ibid, Bull. xxv. (vol. v.), p. 547 (1906). Sir W. Dawson, Joe. cit., 

 p. 208. 



(7)Zoc. cit., p. 209. 



