Microvillus Border (b)

Transverse section across the cilia on the nephrostome. The cilia are arranged 
in rows along the rib-like ridges which are arranged radially around the 
aperture. The mitochondria are associated with the ciliary rootlets.

     ci    =   cilia
     cr    =   ciliary rootlets
     ko    =   kidney opening
     mi    =   mitochondria
     mv    =   microvilli