888 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



greenlandicus, Herr, is also found in the Kome beds of Greenland (21: p. 76). 

 Our present specimen, therefore, is of generic value only, and its presence 

 might support any Cretaceous horizon. Under these circumstances our knowledge 

 of the actual age of 1428 must be based wholly upon the evidence afforded by 

 Gleichenia gilbert-thompsoni. This plant was originally obtained from the 

 Lower Cretaceous of the Shasta series, at Pettyjohn's Ranch, Tehama County, 

 California, in 1882, by the one after whom it was subsequently named by 

 Fontaine. Heretofore it has not been correlated with any particular horizon, 

 for, as Ward observes, ' all that can be said of it is that its age might be either 

 Lower or Upper Cretaceous' (57: p. 233). Nevertheless, its present occurrence 

 in the Skagit river district definitely confirms its character as a Lower Cretace- 

 ous type, and at the same time it enables us to definitely correlate the deposits 

 in which it was found, with those to which Aspidium fredericksburgense belongs. 

 It may thus be confidently asserted that locality 1428 is of the Shasta series. 

 This conclusion gains somewhat in force through the circumstances that locality 

 1436 shows the remains of fern stipes, which have been found to be those of 

 Gleichenia, presumably of G. gilbert-thompsoni. 



Locality 471 is wholly represented by highly altered specimens which have 

 been identified as the rachises of a fern, in all probability of Gleichenia. If this 

 deduction, which is based upon very scanty and poorly preserved material, in 

 which specific characters are not at all recognizable, should ultimately prove 

 correct, we have once more a means of establishing a general correlation between 

 the somewhat isolated Cretaceous areas of British Columbia. A tentative con- 

 clusion with respect to 471 would be that it represents an isolated Cretaceous 

 island which, in the general elevation of the central ridge, was cut off from the 

 lateral areas and subjected to more or less profound alteration as the character 

 of the rock and plant remains suggests. 



While writing these conclusions, a very interesting fact bearing upon the 

 general correlation of the Cretaceous beds has been brought to my notice by Dr. 

 A. W. G. Wilson, of McGill University, who asked me to determine a specimen 

 of fern collected during the past summer. The specimen was a portion of a 

 large slab, which it was impossible to transport from its original location. It 

 was obtained' from the Crowsnest Coal Basin, about thirty miles north of 

 Michel Station, B.C., and it therefore belongs to the same deposits as previously 

 reported upon by me. It, however, adds in most important ways to our knowledge 

 of the very scanty flora hitherto obtained from these beds, since it proved to be 

 a specimen of Aspidium dunkeri, Schimp., which has hitherto been known as an 

 element of the Potomac flora, in which series it constitutes one of the best 

 known and most widely distributed forms (19: p. 101). On this basis it is now 

 possible to correlate the Crowsnest Coal Basin with the Shasta series, and the 

 same may also be said of the deposits on the Nordenskiold river, from which a 

 limited flora has been obtained and studied. 



