part 2] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxv 



by a concentric lamination, and traversed by radial canals : on* 

 very slender evidence, they are said to be allied to sponges and 

 referred to a new genus — AtilcoTcania. • It is impossible to determine 

 their nature ; if they are organic, one cannot definitely assert that 

 they are animal or vegetable. Prof. Garwood discovered 'some 

 curious oolitic structures ' in Spitsbergen, in rocks that are probably 

 Archaean ; but they show no sign of algal origin. 



Geological literature contains many references to a type of rock- 

 structure especially characteristic of Cambrian rocks, named by 

 James Hall in 1888 Gryptozoon, and first described by J. H. Steele 

 in 1825, as calcareous concretions, from Saratoga County (New 

 York). H. P. Cushing, in an account of the Hoyt Limestone of 

 Upper Cambrian age near Saratoga, says that ' perhaps the most 

 striking fossils of the formation are the big, reef -like masses of the- 

 organism of unknown nature, known as Gryptozoon '. A smooth 

 surface of rock containing specimens of Hall's type-species shows- 

 groups of concentric lines forming complete circles or segments 

 of circles cutting one into the other. The matrix in well-preserved 

 specimens is said by Hall to be traversed by minute canals. Dr. 

 G. Ii. Wieland, who described examples from Cambrian strata in 

 Pennsylvania, suggested Gryptophycus as a more appropriate name, 

 since it definitely implies an algal nature, although of this there 

 would seem to be no satisfactory evidence. On the other hand, 

 Prof. 0. Holtedahl, who records the occurrence of Gryptozoon in 

 Cambrian strata in Norway, in Lower Palaeozoic rocks in Ellesmere 

 Land, North -East Greenland, and Spitsbergen, states that similar 

 structures have been found in Triassic strata. This author advocates 

 the employment of Dr. Ernst Kalkowsky's term Stromatolith. 

 The same type of structure has been discovered in Pre-Cambrian 

 rocks in the Belcher Islands of Hudson Bay, and in other regions 

 of North America. 



A. Kothpletz gave a full account of Gryptozoon, and recognized 

 several distinct forms : he believed it to be organic, but left the 

 genus suspended between the animal and the plant kingdoms. In 

 view of the general belief of those who have examined actual speci- 

 mens of Gryptozoon and studied them in situ that its structure is. 

 organic in origin, I hesitate to express a contrary opinion. Grypto- 

 zoon may be the skeleton of an animal ; I do not think that it is 

 a plant. An examination of the published figures and photographs 

 and a perusal of the descriptions lead me to express the opinion 



