from the grey granular intermediate matter which they tra- 

 verse. So far as observed, the canals are confined to the inter- 

 mediate layers, and do not seem to penetrate the primary 

 laminae, though these sometimes present a reticulated appear- 

 ance, and seem to have occasional spaces in them which may 

 have been communicating pores or orifices." 



In the same paper from which the above descriptions have 

 been taken, Dawson describes two additional species : — ( 4 ) 



Cryptozoon boreaie. — "Consists of a mass of cylindrical 

 or turbinate branches, proceeding from a centre and also 

 budding laterally from each other. Each branch shows a 

 series of laminae concave upward. The spaces between the 

 thin laminae are filled with a very fine granular material in 

 which are canals, less frequent, straighter, and more nearly 

 parallel to the laminae than in the typical species. This 

 species is remarkable for the slender and coral-like shape of 

 its branches." The specimens were obtained at Lake St. John, 

 Quebec, in rocks of Trenton (Ordovician) age. 



Cryptozoon occidentale. — This species was described from 

 imperfectly preserved specimens obtained from the Grand 

 Canyon, in Arizona, and from rocks which have been classed 

 as "Pre-Cambrian" (corresponding to the Kewenian of Lake 

 Superior, and the Etcheminian of southern New Brunswick), 

 and therefore belonging to the lowest known fossiliferous 

 horizon. Dr. Dawson says: "Though most of them were im- 

 perfectly preserved, one of them exhibited the concentric 

 laminae of Cryptozoon, and the intermediate layers composed 

 of microscopic grains which were ascertained by Dr. Adams 

 to be partly siliceous and partly calcareous (dolomite and 

 calcite). Instead of the irregular curving canals of the typical 

 Cryptozoon, where best preserved they show ragged cells, 

 giving off on all sides numerous small tortuous and branching 

 canals, but their structure I regard as possibly corresponding 

 to that of Cryptozoon, and I would therefore venture to name 

 the species C. occidentale in hope of the discovery of better 

 specimens." 



Two other doubtful determinations may be mentioned 

 on the authority of Dr. Dawson. < 5 ) In 1885, Professor N. H. 

 Winchill named a Stromatopora-like form C. minnesotense, 

 from the Upper Cambrian of Minnesota ; and Dr. Dawson 

 named another form from the Calciferous (Lower Ordovician) 

 of Lachute, Province of Quebec, but the author states : "I can- 

 not positively affirm that this is a distinct species, but may 

 provisionally name it, C. lachutense." 



WLoc. cit., pp. 207 and 208, figs. 1-3. 

 (5)Xoc. cit., p. 206. 



