海链藻(Thalassiosira)与圆筛藻(Coscinodiscus)的形态学比较研究

海链藻属（Thalassiosira）和圆筛藻属（Coscinodiscus）的种类繁多，是硅藻门中的大属和代表属。两者的形态学特征具有较多相似之处，易混淆鉴定。通过光学显微镜和电镜观察，比较研究了海链藻和圆筛藻种类的形态学特征。海链藻种类除了具有1~2个唇形突之外，还具有数量较多的支持突，少数种类具有闭合突；筛膜位于壳面内侧；中孔在壳面外侧。而圆筛藻种类只具有数量众多的唇形突，且其中两个较大；筛膜位于壳面外侧；中孔在壳面内侧。由于两属形态学特征的区别只有在电镜下才能清晰观察到，因此尚有较多的分类修订工作需要进行。

Morphological Characteristics Comparisons Between Thalassiosira and Coscinodiscus

Thalassiosira(Cleve) Hasle and Coscinodiscus(Ehrenberg) Hasle & Sims are large and typical genera in diatoms. Due to many similar morphological features, it is easy to misidentify between these two genera. Under light microscope and electronic microscope, their morphological characteristics comparisons have been studied. Besides 1-2 rimoportulae, Thalassiosira species have many fultoportulae and several species have occluded processes. The cribra locate close to the internal valve face and the foramens distribute on the external valve face. Contrarily, in terms of Coscinodicus species, the cribra locate close to the external valve face and the foramens distribute on the internal valve face. Without fultoportulae and occluded processes, Coscinodiscus species only have many rimoportulae. Allied Thalassiosira and Coscinodicus taxa should be re-examined and revised to confirm their taxonomic positions.