GYMNOSPERM/E. 39 



CouUsia, and in the Armissan form even the imbricated regions are shorter and more 

 densely clothed than any of the corresponding parts in the Bovey species. The cones 

 figured are smaller and seated upon thicker stems, and their general resemblance does 

 not seem snfficient to outweigh the distinctions seen in the foliage. 



It therefore appears that the forms included under the name of Sequoia CouUsia 

 represent at least two, and possibly three species. 



The first, S. Coutfsice, distinguished by the exceptional delicacy of its foliage, which* 

 in this respect, resembles certain species of Cupressus.^ It ranges in England from the 

 Bournemouth beds, where it is rare, through the Bembridge to the Hempstead series. 

 This species has not hitherto been met with out of England except at Bilin. 



The second and more robust northern form, I should propose to name after Mr. 

 Whymper, from whose specimens it was described. S. Whymperi approaches more 

 closely to the existing S. gigantea, and possessed foliage, cones, and seeds, of approxi- 

 mately double the size of those of S. Couttsia. It is abundant in the Tertiaries of 

 Greenland, Spitzbergen, the Mackenzie, and Baltic. Some portions of foliage, which 

 seem clearly to belong to it, are separated as Glyptostrobus TJngeri. These, while usually 

 associated with Sequoia cones, are never accompanied by any trace of the persistent and 

 very distinct cones of Glyptostrobus, and the infloresence, said to be of Glyptostrobus,^ is 

 absolutely indistinguishable from that figured as Sequoia in the ' Flora of Bovey,' pi. ix, 

 fig. 43. S. Whyn/peri appears in fact to be another instance, like S. polymorpha, of a 

 wide-spread species with so-called dimorphic foliage ; and, besides the supposed Glypto- 

 strobus TJnyeri, I should also feel inclined to unite with it the S. Lanysdorjii figured in 

 the ' Flora Arctica,' vol. 1, pi. xlvii, fig. 3, and vol. 2, pi. xhv, fig. 2, the A. Slernberyi 

 from Oeningen,^ Sinigaglia, and Turin, and from the newest stage of the Lignitic series of 

 America. It is, and must always be, impossible to describe the extinct Sequoias satis- 

 factorily without first realising that the now nearly completely separated types of foliage 

 were formerly very generally united in the same species; and also that constant and 

 accentuated differences, though perhaps unimportant relative to living trees, when met 

 with and found to be persistent in fossil species, mark clearly either a difference in age 

 between deposits, and therefore a stage in evolution, or else a change in temperature 

 or other physical conditions, and must therefore be recorded and distinguished by the 

 palaeontologist. 



The third. Sequoia polymorpha of Saporta, seems principally confined to the Oligo- 

 cenes of the south-east of France. 



These species may have lived contemporaneously, yet in different regions ; the 

 northern form certainly descended as far south in the later Miocene periods as Central 

 Europe. 



^ C. sempervirens, C.funebris, C. torulosa, C. macrocarpa, &c. 



2 ' Fl. Arct.,' vol. iv, pi. xi, fig. 8. 



3 ' Fl. Tert. Helv.,' vol. i, pi. xxi, fig. 5. 



