The morphological variability of two biostratigraphically important diatom species of the Russian Far East, Alveolophora areolata (Moisseeva) Moisseeva and Alveolophora bifaria Nevretdinova et Moisseeva,was studied using light and scanning electron microscopy. High variability was found in mantle height, diameter, stria organization, areola location on the valve face, alveolus structure and costae of A. bifaria, but less variability in A. areolata. Separation valves of A. areolata lack spines, and rimoportulae were found on the valve face for the first time. Based on the new morphological data, descriptions for these taxa have been emended.

中文翻译：

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Alveolophora areolata (Moisseeva) Moisseeva 和 Alveolophora bifaria Nevretdinova & Moisseeva 的形态变异

使用光学和扫描电子显微镜研究了俄罗斯远东两种生物地层学上重要的硅藻物种 Alveolophora areolata (Moisseeva) Moisseeva 和 Alveolophora bifaria Nevretdinova et Moisseeva 的形态变异性。A. bifaria 的地幔高度、直径、纹路组织、瓣膜上的乳晕位置、肺泡结构和肋骨的变异性很高，但 A. areolata 的变异性较小。A. areolata 的分离瓣没有刺，在瓣膜表面首次发现了rimoportulae。根据新的形态学数据，对这些分类群的描述进行了修正。