78 



G. J. de Fej e rvary: 



posterior part, and corresponding to the praefrontal shield , is 

 detached from it (cfr. Fig. 4). This very often happens 

 quite simply in the course of maceration. Its ventral surface 

 indicates always very well the true outlines of the bone, because 

 the mentioned exoskeletal plate adheres to its Upper surface. 

 The secondary formation which occurs on the anterior part of 

 its dorsal surface under the form of an ,,incrustation'*, correspon- 

 ding to one half of the frontonasal shield, adheres so much to the 

 roof of the nasal bone that a detachement of it seems to be impossible 

 (see Fig. 4 c). 



Figure 4 a— d. Figure 5. 



As regards the 1 aminasupr aciliar is, it is homologous with 

 the mentioned [exoskeletal] elements, representing thus a 

 throughout secondary formation. Its bionomical rule is certainly 

 very important because it protects the eye. Its anterior part closely 

 adheres to (Ophisaiirus) , or rather coossifies with [Trachysaiirus) , 

 the supraorbital bone (a primary dermal bone). The upper surface 

 of this supraciliary lamina, — consisting of large plates, the supra- 

 ücularies, and a lateral series of smaller plates, the socalled supra- 

 ciliaries — is rough; its ventral (orbital) surface is rather smooth 

 and on this side the morphological structure of the single plates 

 can be very well established. If we examine the ventral (orbital) 



