FOSSILS OF GRAND CANYON SERIES 233 



but if SO its affinities are nearest to Cryptozoon of Hall. In returning 

 the specimen, in 1883, Sir William sent a note, and later gave the form 

 a specific name. 



Cryptozoon ? occidentale, Daivson 



(Plate 23, figures 1-4.) 



Cryptozoon occidentale, Dawson, 1897. Canadian Record of Science, vol. vii, page 

 208, figure 3. 



A very brief description of the form is given and a microphotograph 

 of a portion of a thin-section. The structure is regarded as possibly 

 corresponding to that of Cr^^ptozoon. 



In the note received in 1883 Sir William wrote : 



"The specimen presents, both on the weathered surfaces and in slices, a lami- 

 nated appearance, tlie laminfe being thin and distant from one another from J mm. 

 to 2 mm. They are somewhat unequal in dii'ection as well as unequal in distance. 



" The laminae are composed of silica, and the intervening spaces are filled with 

 granules and bands of silica imbedded in calcite. When the calcite is removed 

 the silica seems to consist of cr3'stalline granules which are so arranged as to give 

 with tlie calcite a netted appearance, sometimes assuming the aspect of irregular 

 tubular cavities lined with silica. No finer structures are to be observed. If such 

 existed they are probably masked by the crystallization of the silica. 



'■ It would be rash with such material to regard these objects as organic. Some- 

 thing as to this may be based on their mode of recurrence, and possibly new speci- 

 mens may reveal more distinct structure. So far as the present specimens are con- 

 cerned, if organic I should suppose them to have been arenaceous tests of some 

 creature allied to that which produced the Ordovician and Cambrian fossils known 

 as Crj^ptozoon, Hall. These present thin laminae with the interstices occupied with 

 an arenaceous substance perforated with innumerable curved tubes and chamber- 

 lets. The structure on the whole has more resemblance to that of the Carbon- 

 iferous and Tertiary bodies known as Loftusia, Carpenter. The species L. colum- 

 biana, described by Dr G. M Dawson, from the Carboniferous rocks of British 

 Columbia, though small in size, more regular and more distinct in structure, is 

 that which most nearly resembles Cryptozoon and also the Grand Canyon species. > 

 If really of pre-Cambrian age, it merits more extended and detailed study with the 

 aid of additional specimens, as it may form a connecting link between the Cam- 

 brian Cryptozoon and the Laurentian Eozoon. 



" I may add that in addition to C. proliferum of Hall fi'om the Potsdam of New 

 York and C. Minnesotense, Winchell, from the Cambro-Silurian of Minnesota, I 

 have two other forms differing in details of structure. One of these is from the 

 Calciferous of Lachute in the Ottawa district, the other from lake Saint John on 

 the Saguenay, where it was collected by Mr Chambers, of Montreal. I have 

 named them provisionally C. lachutense and C. boreal.* It may further be stated 



* The first of these may be described as in large masses witii irregular waving laminae, some- 

 times apparently connected by pillars and large interstitial canals or spaces. The second is in 

 elongated lobed masses with laminse somewhat waving and in groups, the interstitial canals very 

 fine. 



