The Yorkshire jurassic flora. I. Thallophyta-pteridophyta / Йоркширская флора юрского периода. I. Thallophyta-pteridophyta

THE study of the Yorkshire Jurassic flora was begun by the founders of Palaeobotany, and many have added to it. It is the standard Middle Jurassic flora and my aim in writing this  monograph has been to make the knowledge of it more available and complete. Seward did this in his catalogue in 1900, but since then more has been learnt about every species and the information has been published in upwards of a hundred scattered papers. Advance has, however, been uneven and half the species were neglected entirely. Thus half the material in the present monograph is a compilation of published work and half is new.  <...>