24 Stopes, a New Fern from the Coal Measures. 



circular borders are equally a gymnospermic feature. 

 Though we may find here and there instances to the 

 contrary, taken as a whole there are few things so 

 characteristic of the asexual pteridophyte and the asexual 

 gymnosperm respectively, as the markings on their wood 

 elements. Were the distinction between these elements 

 with multiseriate pits and those with scalarlform marking 

 so unimportant as many suppose, then one would expect 

 to find the former type among the ferns of to-day, but 

 this, so far as I can ascertain, is not the case. Now the 

 Botryopterideae, though they have scalariform elements, 

 have many elements with series of pits recalling a L'ygino- 

 dendron and other primitive gymnosperms, and it appears 

 that in this, and perhaps in this alone, they are not abso- 

 lutety true ferns, but have taken one step towards gymno- 

 sperm-anatomy. Other considerations lead one to suppose 

 that they may be the group from which the Pteridosperms 

 sprang, and it is not surprising that while perhaps remain- 

 ing true ferns in every other sense of tht word, some of 

 them have assumed one feature in advance of the general 

 run of ferns of to-day. As one of the openers of the 

 discussion at the Linnean Society on the " Origin of 

 Gymnosperms" this March (1906), Mr. Arber stated that 

 there was every reason to believe that true ferns did exist in 

 the FalcBozoic, and that these would belong to a class from 

 which both Leptosporangiate and Eusporangiate groups 

 arose. To this old stock he gave the name " Primofilices," 

 and stated that the Botryopterideae constitute one of its 

 families, adding that the origin of the modern ferns from 

 the Primofilices is clear. The point at present under 

 consideration is whether the Botryopterideae are really 

 members of the group Primofilices in the true sense of the 

 word, which presupposes that its members shall be at least 

 as primitive as those living to-day. Many of the Botry- 



