ON THE GREENLAND RIGHT-WHALE. 97 



iif. The most posterior part of the same surface, lined by an ossified cartilaginous 



layer from the primordial cranium. 

 n. The inner surface of the nasal bone meeting the corresponding surface of the other 



nasal bone. 

 rø\ The inferior surface of the nasal bone. 

 0. The surface of the section of the occipital. 



o' . The inferior and posterior part of the free surface of the occipital. 

 0^. The superior part of the same surface. 

 0°. The occipital foramen [foramen magnwii). 

 p. The palatine. 

 t. The temporal. 

 u. The pterygoid. 



V. The right internal surface of the vomer. 

 w'.The surface of the section of the vomer in the mesial line. 

 v. The external surface of the vomer, as far as it is covered by the superior 



maxillary. 

 v". The same surface, as far as it is covered by the left palatine bone. 

 «". The same surface, as far as it forms the internal wall of the nasal canal. 

 V. The posterior free extremity of the vomer. 

 z. The zygomatic. 



The lower jaw of our forty-seven and a half feet long Greenland whale skeleton will be 

 found represented, as seen from behind, in Plate II, fig. 2; its left ramus, as seen from 

 the outside, in Plate II, fig. 1; the right ramus, as seen from the inside, in Plate V, 

 fig. 2 ; and finally, the posterior extremity of the same ramus, as seen from above, in Plate V, 

 fig. 3. 



Compared with the rami of the lower jaw in the newborn Greenland whale, those of the fully 

 grown animal are unquestionably much curved, but by no means so much as those of the rorquals 

 in general, more especially those of the humpbacks (Plate III, fig. 2). The curvature, it will be seen, 

 is also completely limited to its anterior half. This is evidently caused by the glenoid articulation 

 being placed so outwardly on the greatly projecting lateral processes of the temporal bone that 

 even at this place they are separated from each other by the breadth of the entire skull, whereas 

 in the rorquals, as we have stated already (compare Plate III, figs. 2 and 3), the case is quite 

 different. As the branches of the lower jaw of the full-grown Greenland whale, though 

 bounding the enormously broad cavity of the mouth, and though approaching very close to each 

 other at the symphysis, are comparatively but slightly curved, so they must also, on the whole, be 

 called slender, that is, in comparison with the branches of the lower jaw of the humpbacks, although 

 they are so heavy that a single one of them in its recent state can scarcely be lifted from the 

 ground by the united efforts of six men. It is only in their hindmost ends that their thickness is 

 very great ; towards the front it gradually decreases, so that at their points they become com- 

 pletely flattened. Their great weight depends, accordingly, partly on the thickness of their 

 posterior ends, partly on their extraordinary length. (See especially PI. II, fig. 2, where, however, 

 some allowance must be made for the diminution of the anterior ends, nineteen feet distant, in con- 

 sequence of the perspective.) 



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