443 



deep and narrow groove, which lodged the muscles of the eye-ball. The median anterior 

 part of the bone unites with both orbitosphenoids and alisphenoids, and external to this is 

 the broad sutural surface for the squamosal. The straight median margins of the f rentals 

 are thinned off and joined by a squamous frontal suture, the right overlapping the left. The 

 whole posterior and lateral border of the frontal, as far as the junction with the squamosal, 

 presents a broad, oblique, sutural surface, which joins, by overlapping, the .contiguous border 

 of the occipital. The smooth cerebral surface of the frontals is flat at the middle, arched at 

 the sides, and not impressed by any convolutions. The vomer expands into two aliform 

 processes at its base, which is applied against the presphenoid and orbitosphenoids ; it then 

 becomes subcompressed and smoothly excavated, but much more deeply at the left side, where 

 it forms the inner and posterior boundary of the single nasal meatus : it again slightly expands, 

 and afterwards is continued, gradually decreasing, to near the anterior end of the premaxil- 

 laries. There is no trace of nasal bones. The bone, formed by the coalesced prefrontals, 

 penetrates the posterior part of the groove of the vomer, above which it expands, unequally, 

 into an obtuse prominence rising and inclining to the left side : it is grooved on both sides, 

 and forms the septum of the vertical nasal passage. 



The palatine and pterygoid bones articulate with the sides of the expanded base of the 

 vomer : the margins of the canal excavated in the upper surface of the rostral production of 

 the vomer are overlapped by the premaxillaries. 



The palatal is a small, triangular bone, thickest anteriorly, thin, produced and bent poste- 

 riorly and above : it commences here by its attachment to the anterior and outer angle of the 

 vomer, bends forwards, downwards and inwards to circumscribe the nasal meatus, and receives 

 in a groove on its upper and anterior border the palatine prominence of the upper maxillary 

 bone. The whole posterior border of the palatine fits into a groove of the contiguous border 

 of the pterygoid. The pterygoid, which is double the size of the palatine *, extends back- 

 wards to the basioccipital, articulating in its progress by its expanded upper border with the 

 pre-, basi- and ali-sphenoids : from this border the bone descends, arching inwards towards 

 its fellow, which it joins along the anterior half of its extent : the remaining free border is 

 divided from this by a deep notch, and circumscribes the large posterior bony aperture of the 

 nostril. 



The maxillary expands from its palatine prominence the essential point of its suspension 

 backwards, outwards, but chiefly forwards, where it gradually diminishes to an obtuse 

 point. It contracts an union posteriorly with the orbitosphenoid and alisphenoid, and very 

 extensively with the frontal. The malar bone is wedged into the outer interspace, between 

 the maxillary bone and the orbital process of the frontal. The nasal process of the maxillary 

 is traversed by a large vertical canal. The premaxillaries are applied against the whole inner 

 surface of the maxillaries between them and the vomer. The right extends much farther 

 back than the left. The capacious basin on the upper surface of the skull, which lodges the 

 valuable product called ' spermaceti,' is formed by the expanded and concave nasal processes 

 of the premaxillaries and maxillaries, which overlap the frontals : a stout ridge divides the 



* All the primary, central and essential bones of this cranium are small : development and expan- 

 sion have had their influence chiefly in the subsidiary and peripheral pieces. 



3L2 



