34 Later Extinct Floras of North America, 



of the Miocene of Europe; differing from that well-known 

 Bpecies only in the uniform rounding of the bases and summits 

 of the Leaves. The plant which lias been doubtfully referred 

 to Sequoia Langsdorfii, would probably be accepted by for- 

 eign botanists as identical with that species, but, for the rea- 

 Bons given in the remarks upon that plant, it seems to me tpiite 

 doubtful whether it was a Sequoia, and more probable that it 

 was a Taxodium allied to our deciduous cypress. 



The great fan palm collected by Dr. I lay den seems to be 

 a representative of Sabal major of the European Tertiaries and 

 Sabal palmetto of our Southern States. From both these, how- 

 ever, it is distinguished by the larger number of folds in the 

 leaves, and from S. major by its flat, unkeeled petiole. 



The numerous 6pecies of PojpuVm of which descriptions are 

 now given will not fail to attract the attention of those whose 

 rot runs in tin's direction. Several of them seem to be 

 new to science, and show, for the most part, a greater affinity 

 with the foreign poplars, /'. alba, &c, than with the species 

 more common on this continent; though a single one, /'. 

 '/'/"//•/'■'' N. evidently belongs to the group of which our balsam 

 poplar may be taken as the type. The little species described 

 under the name of /'. rotundifolia presents some anomalies 

 in form and structure as compared with most of our poplars, 

 but its resemblance to another species contained in this collec- 

 tion, P. elldptica, and to one contained in the collection of 

 the North-west Boundary Commission, described under the 

 name of P.fiabeWum, baa induced me to class them together 



Among living specie- it has a striking analogue in Pqpulu8 



prui$u>8a, now growing in Songaria. 



The several specie- of PlatanUS, which the collection con- 

 tain-, form a striking and Interesting portion of this group of 

 planl-, and all seem distinct from the fossil species hitherto 



described, and from any now living. < >f our American Byca-i 

 mores, the leaves of P. oocidentalis are much more toothed, 

 while those of P. raoemosa are more deeply lobed than any of 



