88 ESCHRICHT AND REINHARDT 



extremities of the intermaxillaries even spread out to both sides in the shape of a pair of wings, 

 except by a distortion, occasioned by the drying of the bones, which at this place are compara- 

 tively thin. 



While the palatine surface of the upper jaw is chiefly formed by the superior maxillaries, its 

 superior surface is, on the other hand, chiefly formed by the intermaxillaries. As these bones 

 were seen on the palatine surface to enclose the anterior obtuse point of the primordial vomer 

 above and on either side, they also cover in the same manner this enormous cartilaginous 

 structure in its entire length, as far as the anterior angle of the nasal aperture, and they will 

 be found to occupy by far the greater part of the superior surface of the whole upper jaw. Near 

 this aperture they diverge from each other to form the greater part of its free margin, except only 

 the most posterior part, where they are replaced by the nasal bones («). Behind the opening 

 they enclose the nasal bones ; and then, as usual, they meet the frontals. The margin of the 

 nasal opening formed by them and the nasals is so much elevated, especially behind (Plate II, 

 flg, 2 i — n), that it may be compared to a tube, though certainly a very short and wide one. 

 This tube points upwards and forwards ; it inclines a little outwards to either side (Plate IV, 

 fig. 1), by which its side walls become visible ; in front, on the contrary, it is, as it were, somewhat 

 compressed at the sides, and gradually disappears in the part of the intermaxillaries just 

 before it. 



On either side of the intermaxillaries the superior maxillaries occupy a comparatively small 

 part of the superior surface of the upper jaw at the nasal opening, where its border is turned a 

 little outwards ; this border hides them completely in the newborn individual. Behind the 

 opening, on the contrary, the superior maxillaries seem even to have far greater dimensions in the 

 Greenland whale than in the rorquals, appearing here in the form of a triangular plate, the posterior 

 edge of which meets the frontal in its whole outward extent, and the exterior part of which is 

 continued in the orbital process already mentioned. This triangular plate is by no means 

 wanting in the rorquals, but in them it is covered by a projecting portion of the frontal, in such 

 a manner as to appear divided into two prolongations, one of which (Plate III, figs. 2 and 3, m') 

 extends backwards and inwards to meet the anterior edge of the frontal, the other [m°) is prolonged 

 outwards as an orbital process. 



The nasal bones (Plate III, fig. 1 ; Plate II, fig. 2 ; and Plate IV, fig. 1 : n) are placed in the 

 Greenland whale, as in the Cape whale, just behind the nasal opening in the shape of two elon- 

 gated rectangular osseous plates, which, unlike to those of the rorquals, are about equally broad 

 behind and before. Their anterior half had in our largest specimen a remarkably dark colour 

 and a more brittle texture (Plate IV, fig. 1 n), which was certainly only accidental. As has just 

 been mentioned, though on the whole placed in a horizontal position, they are perceptibly elevated 

 in their anterior parts, together with the adjoining part of the intermaxillaries, so that they become 

 visible from behind (Plate II, fig. 2, n), whereas the frontals are hidden between them and the 

 squamosal portion of the occipital bone. 



As is usually the case in all cetaceous animals, only a small part of the frontals is left 

 uncovered on the superior surface of the skull, yet a greater part than that left uncovered in the 

 fin-whales. It is also remarkable, that they are by no means more, but rather less, covered by 

 the squamous portion of the occipital bone in the full-grown individual than in the new- 

 born one. Close to the middle line from their anterior edge a pair of narrow prolongations 

 extend to the posterior edge of the nasal bones, and are enclosed like the latter by the posterior 



