ADAMS: SKULL OF THE WOLF-EEL. 337 



Lateral Face. (Plate XXX, fig. 22.) 



The lateral faces are rather smooth, but are depressed at 

 the posterior edge, this edge being drawn out laterally to en- 

 large the posterior face. 



Dorsal Face. (Plate XXX, fig. 21.) 



The upper or dorsal face forms the postero-ventral part of 

 the brain-case. It is set up above the rest of the bone, as are all 

 of the bones forming a part of the brain-case. It is marked 

 by numerous pits and cavities. 



Anterior Face. (Plate XXX, fig. 21.) 



The anterior part of the basioccipital is marked by a deep 

 groove. It inclines ventrally and posteriorly at the expense of 

 the ventral face. The lower part of the groove has a thin 

 tongue of bone extending about half way to the dorsal edge. 

 This groove articulates with the parasphenoid. 



Articulations. 



The basioccipital has six articulations : With the parasphe- 

 noid, prootics, exoccipitals and the first cervical vertebra. It 

 articulates with the parasphenoid by the groove in the anterior 

 face, with the prootics and exoccipitals by the edges, and the 

 posterior face with the cervical vertebra. 



Epiotic. (Plate XXXI, figs. 29, 30, 31; plate XXVIII, fig. 4.) 



The epiotics are paired bones in the posterior part of the 

 skull. They are placed ventral to the supraoccipital, against 

 the pterotics, their anterior face forming a part of the brain- 

 cavity. They are twice as long as wide, the long axis of the 

 bone being placed transversely across the occipital region of 

 the skull. The epiotics have three faces to consider. 



Inner Face. (Plate XXXI, fig. 29.) 



The inner face is roughly square in outline and the part of 

 the bone forming the brain-case is covered with a thin plate of 

 bone, as usual. This disc is pitted and is generally concave. 

 The face articulating with the pterotics is concave and is 

 marked with numerous ridges which fit into corresponding 

 grooves on the pterotic. 



Outer Face. (Plate XXXI, fig. 30.) 



The outer face is concave on the short axis and is roughly 

 rectangular in shape, the outer end being narrowed down to a 

 rounded projection. The face articulating with the pterotic 

 is at right angles to that forming a part of the brain-case. 



