In type A,the warty layer is absent or rare in pit chamber and in type B, the warty layer is present,in this paper,the variation in phylogeny of the pit membrane in bordered pits is also discussed.

• A 型是指纹孔室内瘤状层缺乏或罕见,B型则具明显的瘤状层。 并对具缘纹孔在系统发育中的变化进行了讨论。