PHYTODEBRIS FROM SCOTTISH SILURIAN AND LOWER DEVONIAN CONTINENTAL DEPOSITS

A palynological investigation of Scottish Silurian and Lower Devonian continental deposits revealed rich microfossil assemblages comprising dispersed sporomorphs and fragments (''phytodebris''). The fragments, which comprise filaments, tubular structures, associations of tubular structures and cuticles, are described and their affinities and palace obotanical implications discussed. The filaments are interpreted as fu ngal in origin, and the majority of the tubular structures are believe d to derive from nematophytes. Most of the cuticles are also believed to belong to the nematophytes, although some may represent cuticles de rived from higher land plants. The assemblages of fragments from Scotl and are similar to those described from contemporaneous strata from el sewhere indicating that the organisms from which they derive were geog raphically widespread. In addition to phytodebris, fragments of arthro pod cuticle were also recovered and are described. Four species of tub ular structure (Laevitubulus frondifera Wellman, sp. nov., Porcatitubu lus microspiralis Wellman, sp. nov., Porcatitubulus microannulatus Wel lman, sp. nov. and Porcatitubulus strupus Wellman, sp. nov.) and one s pecies of filament (Ornatifilum lornensis Wellman, sp. nov.) are propo sed as new.