94 BRITISH FOSSIL REPTILES. 



the Iguana and most Lacertilia, and as it is in the Grocodilia. Each half of the 

 frontal in Scelidosaurus is a long, inequilateral triangle, the medial being the 

 longest side, the posterior, which joins the parietal, the shortest ; the antero- 

 external border is irregularly and deeply notched, uniting with the post-frontal, 

 super-orbital, pre-frontal, and nasal bones ; it is excluded, as in Lacerta proper, by 

 the large super-orbital bone (71) from the orbit. The outer surface of the frontal 

 is sculptured by irregular lines and grooves, but less deeply than in Crocodilus. 



The post-frontal (12) forms the back and part of the upper border of the 

 orbit, uniting with the super-orbital, the frontal, and malar, and sending 

 backward an angular process to join the mastoid, completing the upper bar 

 or zygomatic arch of the temporal fossa. This arch had been broken away on the 

 left side (PI. 45), but is preserved on the right side (PL 46, 8, 12). 



The pre-frontal (Pis. 45, 46, 14) presents a horizontal and a vertical portion ; 

 the former and larger part is wedged between the frontal, super-orbital, and nasal 

 bones, the descending plate joins the lacrymal (73), and touches the upper angle of 

 the maxillary (21). In the Crocodile the aspect of the whole outer plate of the 

 pre-frontal is upward ; in some Lacertians the major part looks outward. 



The nasal bones (15, Pis. 46, 47) unite above and behind with the 

 frontal (11) by a short border, obliquely and irregularly cut, to include the 

 pointed anterior ends of the lateral halves of the frontal; the nasals expand 

 as they advance, in union, first, with the pre-frontals, then with the maxillaries, 

 where they slightly decrease in breadth. The outer plate of the nasals looks 

 upward; the maxillary border is slightly bent down (15, fig. 2, PL 46), and 

 is overlapped by the maxillary (21, ib.). The mutilated fore part of the skull 

 precludes the determination of the relations of the nasals with the pre-maxillary, 

 and of the character of that bone ; but it most probably repeated, in the main, 

 the conditions which it presents in Iguanodon.^ 



The fracture shows the superior thickness of the median and lateral borders of 

 the nasals, the intervening part being, as it were, channeled below for the air- 

 passage ; this has not here been divided by any ossified vertical septum ; the 

 thickened palatal and alveolar parts of the maxillary, as they bend toward each 

 other, present a convexity transversely to the nasal passage. This is closed 

 below, as it seems, by the vomer (PI. 46, fig. 2, 13). 



Of the hind part of the bony palate the pteiygoid was brought into view by 

 removing the matrix between the diverging rami of the mandible. The body of 

 the bone is iu the form of a subtriangular plate, of 1 inch 7 lines extent along its 

 mesial border, which is slightly concave, receding from its fellow at the medial 

 line, or base, as in the Iguana ; the apex extends outward, and a little downward 

 to abut against the fore and inner part of the ectopterygoid. From the hind 



1 Vol. i, p. 521, pi. 49, figa. 9, 22. 



