The intricately sculptured unit at each end of the diatom
The broad surface displaying most of the ornamentation is called the face.
The downturned surface that meets the
is called the mantle.
The morphology of the valve provides many of the features used to classify diatoms.
The silica plate forming one wall of a loculate areola. The velum is perforated with pores. Located on the external or internal wall of the areola, depending on species, opposite the foramen. Plural form is vela.
The side of the valve face that is narrower and less convex than the dorsal side. Occurs in genera that are asymmetrical to the apical axis, such as Cymbella and Encyonema. From Latin for belly.
An interruption in the stria pattern of a raphid diatom valve. The Voigt discontinuity, if present, occurs on the secondary side of a valve and marks the point of fusion of the sternum during ontogeny. Named for M. Voigt, who first noted it in 1943.
A flap of silica projecting from the side of a pore or from a bar crossing an areola. Plural form is volae.