REPORT OF THE CHIEF ASTRONOMER 837 



SESSIONAL PAPER No. 25a 



Nilsonia pasaytensis stands by itself as a species, but reference to the general 

 distribution of the genus shows that although it may be recognized in the Upper 

 Cretaceous, as recorded by Dawson (9 : iv., 24), its range is rather through the 

 Lower Mesozoic. Thus, Ward (57 : p. 90 et seq.) enumerates four Cretaceous 

 species, of which one is from the Kootanie and three from the Shasta series, 

 and six species of Jurassic age, a distribution in exact accord with the limits 

 assigned by Zeiller (59: p. 238), who speaks of its tolerable abundance in the 

 Rhaetic, whence it passes through the Jurassic to the Lower Cretaceous. The 

 general evidence of distribution, therefore, is toward greater abundance in the 

 Middle Mesozoic rather than toward its close, and in this sense the present 

 species would afford very strong evidence of a Lower Cretaceous horizon. 

 Furthermore, in comparing this species with those previously described by 

 Fontaine and others, there is seen to be a somewhat remarkable correspondence 

 with N. nipponensis, Yokoyama, as figured by Ward (57 : pi. xvii., f. 8-10), 

 which tends to strengthen the idea that this is at least an early Cretaceous type. 



Aspidium fredericksburgense, Font., is an exceedingly well characterized 

 plant, and there can be little doubt that the same species occurs in the flora of the 

 Pasayten river district. It was originally described by Fontaine (19: p. 94, pi. 

 xi. and xii.), from the Potomac formation at Fredericksburg, Virginia, where 

 it is said to be one of the most common ferns. 



Reviewing this evidence, we observe that there are eleven species of plants 

 from locality 1430. Of these Dorstenia ( ?), which is of questionable character, 

 and Pinus, which is chiefly represented by seeds and may indicate any one of 

 several horizons, need to be eliminated because not specifically defined. This 

 leaves nine well-defined species, of which three are definitely Lower Cretaceous 

 and six as definitely Upper Cretaceous. These differences, however, are fully in 

 accord with the correlations already established by Dawson (9: iv., 19'), and by 

 Diller and Stanton (17: p. 476; and 18: p. 435, etc.), and we may conclude that 

 at least that portion of the flora from the Skagit river which is embraced in 

 locality 1430, is of Shasta-Chico age, and that it shows two well defined horizons 

 within that series. 



Directing attention to locality 1428, about which a specific question was 

 raised with respect to its age relatively to that of 1430, it is possible to give a 

 very definite answer. This locality has furnished four specimens of plants 

 only. Of these one species of Salix presents nothing in the nature of reliable 

 evidence, and it shows no contact with the other localities. Pinus is represented 

 by fragments of leaves and seeds which also appear in locality 1433, which is 

 presumably of the same age. Glyptostrobus, bearing a certain resemblance to G. 

 europseus, appears only in this locality, and it may or may not be comparable 

 with G. gracillimus, Lesq., which Dawson has described from the Niobrara 

 horizon of British Columbia (9: iv. 21). But it may be recalled that Dawson 

 (9: iv., 25) directs attention to a species of Glyptostrobus from the Upper 

 Cretaceous of Vancouver island, which he refers to as comparable with G. 

 europaeus in form and size, but too obscure for certain determination. Further- 

 more, Knowlton (37) enumerates nine species of Glyptostrobus, of which five are 

 Cretaceous, chiefly from the Kootanie and Potomac series, while one of these, G. 



