It is customary to divide the rest of the hind-brain into two parts, viz., an upper, called the metencephalon, and a lower, the myelencephalon.    From Wordnik.com.  [IX. Neurology. 2. Development of the Nervous System] Reference

The cerebellum is developed by a thickening of the roof, and the pons by a thickening in the floor and lateral walls of the metencephalon.    From Wordnik.com.  [IX. Neurology. 2. Development of the Nervous System] Reference

The pons is developed from the ventro-lateral wall of the metencephalon by a process similar to that which has been described for the medulla oblongata.    From Wordnik.com.  [IX. Neurology. 2. Development of the Nervous System] Reference

Developmentally considered, the fourth ventricle consists of three parts: a superior belonging to the isthmus rhombencephali, an intermediate, to the metencephalon, and an inferior, to the myelencephalon.    From Wordnik.com.  [IX. Neurology. 4a. The Hind-brain or Rhombencephalon] Reference

It consists of (a) the myelencephalon, comprising the medulla oblongata and the lower part of the fourth ventricle; (b) the metencephalon, consisting of the pons, cerebellum, and the intermediate part of the fourth ventricle; and (c) the isthmus rhombencephali, a constricted portion immediately adjoining the mid-brain and including the superior peduncles of the cerebellum, the anterior medullary velum, and the upper part of the fourth ventricle.    From Wordnik.com.  [IX. Neurology. 4a. The Hind-brain or Rhombencephalon] Reference