243 



Fig. 2. Ventral surface of the same . nndried skull. 

 Natural size. The dotted line indicates the 

 swerve of the ventral axis of the cranium 

 towards the left side caused by the rotation 

 towards the right of the orbital region of the 

 cranium. The chondrocranium appears on 

 the surface of the cranium in several places, 

 and not always symmetrically. 



Fig. o. Lateral view of the same skull seen from the 

 right or ocular side. Natural size. The 

 right nasal and right lachrymal are here 

 fully shown, and do not appear in perspective 

 as in figs. 1 and 2. 



Plate II. 



Fig. 4. The occipital region of the same skull viewed 

 from behind. Natural size. The dotted line 

 indicates the departure from the symmetry. 

 The chondrocranium appears on the surface 

 between the exoccipitals and epiotics. 



Fig. 5. Lateral (moist) dissection of the opercular 

 bones, palato-pterygoid arcade, and jaw 

 apparatus of the Plaice, on the ocular or 

 right side. Natural size. Extreme length 

 of specimen o4cm. The palatine has been 

 rotated downwards in order to illustrate its 

 shape, and the lower jaw has been depressed. 

 In the natural disposition of the parts the 

 lower end of the maxilla lies external to the 

 mandible. 



Fig. (). Dorsal (moist) dissection of the Hyoid arch of a 

 '■34cm. Plaice. Natural size. In the living 

 animal the stout hyoid bar is almost vertical 

 and the basi-hyal projects forwards at light- 



