贵州早泥盆世刺镰蕨的新观察

刺镰蕨在早泥盆世是一种广布于世界的植物，尽管报道自许多地点，但远未完全地了解它，其主要原因是能育材料罕见。我们观察的标本采自贵州早泥盆世的丹林组。它显示具柄的孢子囊侧生于靠近叶腋的轴上，我们的标本近似球形的孢子囊和它的形态略小于雷诺的肾形孢子囊外，其它方面如：带状的营养轴上具有疏螺旋排列的镰刀状叶，具短柄的孢子囊侧生于轴上以及管胞具穿孔壁等性状与雷诺修订后的刺镰蕨完全一致。我们同意雷诺的观点，将镰蕨目升为纲，与工蕨纲和石松纲并列。它的系统位置是介于工蕨纲和石松纲之间。其下包含一目、一科三个属——镰蕨属、巴拉格瓦纳彻属和星木属。这种植物的生殖部分在中国尚属首次报道。

NEW OBSERVATIONS ON DREPANOPHYCUS SPINAEFORMIS FROM THE LOWER DEVONIAN OFGUIZHOU,CHINA

Drepanophycus spinaeformis Goeppert is a plant of world-wide distribution in the Lower Devonian. Although this species has been reported from numerous localities, it is far from being understood well, because the fertile material is rare. Observation on specimens from the Danlin Formation of Guizhou showed that the sporangia were borne on short stalks attached laterally to the axes near the leaf axil, nearly sphaeroid, and smaller than Rayner' kidney sporangia. Howerer, other character, e. g. banded nutritive axis bearing spiral drepanoid leaves, perforated tracheid wall, are the same as those described by Rayner. We agree with Rayner in raising Drepanophycales to the status of class, Drepanophy-copsida, parallel with Zosterophyllopsida and Lycopsida. The systematic position of Drepanophycopsida is in between Zosterophyllopsida and Lycopsida. The class includes one order, one family and three genera {Drepanophycus, Baragwanaihia and Aster oxy Ian). The fertile parts of the plant are reported for the first time in China.