388 " J^- POLLARD, 



At the middle of the orbital region the epiphysial bar {Eph.) passes 

 across the supracranial fontanelle. In the anterior border of the 

 epiphysial bar at the median point is a notch ^vhere the epiphysis 

 rests. 



In front of the level of the epiphysial bar a portion of the carti- 

 laginous side wall is left and shown foreshortened in the figure (Fig. 5) 

 but there is no antorbital process and no bridge above from the 

 orbital to the rostral region (in other words the olfactory lobes and 

 nerves are not roofed over by cartilage). The internasal septum takes 

 the form of a distinct rostrum which however does not project beyond 

 the level of the anterior narial opening. 



In the cranial floor behind the rostrum is a pair of small fonta- 

 nelles in the cartilage. One is indicated by the shading on the right 

 of the drawing. These lodge minute projections from the base of the 

 forebrain. 



Behind the epiphysial bar the skull cavity widens out very remar- 

 kably. From the epiphysial bar forwards it is much smaller as shown 

 in the figure. The hyomandibular (H.M.) articulates with the skull 

 by an enormously long articulation and only along the articulation 

 does much cartilage remain. There is however a strong process 

 downwards and backwards which supports the operculum without the 

 intermediation of an opercular cartilage. 



Another block of cartilage remains in the symplectic and quadrate 

 region, the intervening portion having been replaced by perichondrial 

 bone. 



A small pterygoid cartilage {Pty, Fig. 9) is independently formed 

 much further forward. It may be seen on the left of the figure partly 

 hidden by the prepalatine piece. The cartilaginous apophyses of the 

 prepalatinc piece {Prepal.) remain as a small portion at the articu- 

 lation near the base of the rostrum and a large distal block. 



Above the prepalatine cartilage is the nasal tentacle with a slight 

 basal expansion. This forms the outer wall of the anterior narial 

 opening. 



The rostrum bears at its tip the upper tentacle-like support of 

 the velum {m.v.s.). A small nodule (»f procartilage is seen on the 

 left between the prepalatine and the velar supports. The maxillary 

 tentacle {Mx. t.) does not rest on the prepalatine piece but is sup- 

 ported by the intermediation of the maxillary bone. Its base is bifur- 

 cated on the left side of the figure. 



The Meckeliau cartilage {Mck.) is represented as a triangular 



