Lateral sternum

A thickened area of silica without pores on the valve face parallel to the sternum and interrupting the striae. One lies on each side of the sternum. The pair connect at the central node, becoming lyrate (having the shape of a lyre). A freshwater example in Mastogloia pumila is illustrated on this page.

Mastogloia Lateral Sternum
Scanning electron micrograph of the lateral sternum of a marine Mastogloia.
Maspumila3 77X232
Image Credit: Loren Bahls
Light micrograph showing the lyrate, lateral sternum of Mastogloia pumila, interrupting the striae on each side of the raphe. Scale bar = 10 µm.