Rhomboid Fossa

The anterior part of the fourth ventricle is named, from its shape, the rhomboid fossa, and its anterior wall, formed by the back of the pons and medulla oblongata, constitutes the floor of the fourth ventricle.

It is covered by a thin layer of gray substance continuous with that of the medulla spinalis; superficial to this is a thin lamina of neuroglia which constitutes the ependyma of the ventricle and supports a layer of ciliated epithelium.

Read more about Rhomboid Fossa:  Parts, Features, Additional Images