780 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



This genus has not hitherto been known to occur in North America in either a fossil or living 

 condition, nor has it been found nearer to this continent than certain of the Pacific islands. 

 Still the hinge characters observable on these Puget estuary specimens leave no room for 

 reasonable doubt that jthey are strictly congeneric with true Batissa. Indeed, a species of that 

 genus which is now living upon the Fiji Islands is closely related to this fossil form. 



Knowlton (in manuscript) has described 365 species of plants from the Puget 

 group. The lower strata are Eocene and the upper are possibly Miocene. The 

 general character and distribution of the flora are stated by Knowlton ^°'' as f oUows : 



The flora of the Puget formation is an exceedingly rich one. Over 100 species have already- 

 been named and described, and from the material in hand it seems safe to assume that the 

 number will reach 250 [365]. Inasmuch as a very large proportion, perhaps more than nine- 

 tenths, of the plants are new to science, it becomes extremely difficult to settle their affinities 

 and determine satisfactorily their bearing on the question of age. It is only by a study of their 

 general facies that results along either line can be obtained. 



While the Puget flora as a whole may be considered relatively uniform, there are well- 

 marked differences between the plants found in the lower beds, as represented at Carbonado, 

 Wnkeson, and South Prairie Creek, and those found in the upper beds at the highest point in 

 the Carbon River canyon, the Clay mine on Green River, Snoqualmie Pass, and at Steels- 

 Crossing near Black River Junction. Certain few genera are found throughout the series, but 

 thus far no species has been noted as common throughout. On the other hand, both lower 

 and higher beds are characterized by a considerable number of genera. Thus Quercus, Juglans, 

 Rhamus, Populus, and Laurus are found from base to summit. The following genera have thus- 

 far been found in the lower beds but not at all in the upper: Qadophle'bis, Lastrea, Dryopteris, 

 Anemia, Calamopsis, Sabal, Siphonites, Ficus, Eucalyptus, and Araha; and the following have 

 been detected in the upper but not in the lower: Rhus, Castanea, Betula, and Platanus. 



The lower beds, on account of the abundance of ferns, gigantic palms, figs, and a number 

 of genera now found in the West Indies and tropical South America, may be supposed to have 

 enjoyed a much warmer, possibly a subtropical temperature, while the presence of sumacs, 

 chestnuts, birches, and sycamores in the upper beds would seem to indicate an approach to- 

 the conditions prevailing at the present day. 



A number of species of plants have been found to be common to the west and east sides 

 of the Cascades. This number is not large, but they are important and easily recognized forms, 

 and there is indication that the number will be increased when the material in hand has been- 

 more thoroughly studied. This would indicate that approximately similar conditions of chmate 

 and topography prevailed throughout this general area during the Puget epoch. The Cascade 

 Range as it now exists did not then intervene. 



The Puget group is well described 'by George Otis Smith, ^^* who brings together 

 the data quoted above, with additional details. 



M 10. SOTJTHEBN BRITISH COIiTJMBIA. 



At the junction of Similkameen and Tulameen rivers, British Columbia, is a. 

 basin containing strata assigned by CamselP^*'^ to the OUgocene: 



These sedimentary rocks alone in the northern part of the district cover an area of nearly- 

 50 square miles, the basin being 14 miles long with a variable width of from 3 to 5^ miles. 

 They consist of thick beds of sandstone, with clay, shales, and several seams of hgnite. The 

 base of the series appears to be a very coarse grained sandstone containing many large rounded 

 white feldspars in a matrix of calcareous material. This rests on the eastern side of the basin, 

 on the Copper Mountain series of rocks [monzonite], while on nearly aU other boundaries the 

 sediments dip under the more recent volcanic rocks, which He as sheets on them. In parts- 



