102 



Dr. H. Burmeister on some Cetaceans. 



These measurements show that the beak is longer than in the 

 Cape species, and relatively shorter than in the European spe- 

 cies, but perhaps of the same breadth ; the teeth-line is longer 

 than in either of them, and the after part, between the orbits 

 and temples, rather smaller and not so broad. Other differences 

 are presented by the forms of the different bones. 



The intermaxillai'ies, which in Orca gladiator are narrowed to 

 the apex, and in 0. capensis are enlarged into an ovate figure 

 (as shown by the drawings in the Voy. Ereb. and Terr. pis. 8 & 9), 

 have a more rounded form in O. magellanica, and are broadest 

 at the apex ; from that point they go in a straight line to the 

 base of the nose, only becoming rapidly narrower near the notch, 

 where the breadth is only 3| inches (at the anterior extremity 4|), 

 and then are extended into the usual elliptical part surrounding 

 the nasal apertures. In consequence of this breadth of the in- 

 termaxillaries in the anterior region, the maxillaries are slender, 

 and narrower than in the other two species. 



In the form of the occiput Orca magellanica agrees rather 

 with O. capensis than with O. gladiator, being larger and having 

 a somewhat excavated surface, and a sharp crest on the whole 

 circumference above. This crest has in the middle a posteriorly 

 protracted angle, into which enters the high protuberance of the 

 frontal bones behind the nasal apertures ; from the edge of this 

 angle a sharp elevated margin or line descends along the middle 

 of the occiput to the great occipital foramen. The sides of the 

 occiput are sloped more backward, as in 0. capensis, and thus 

 form a larger posterior temporal cavity. The tuberosity before 

 and above the orbits seems to be not so high; but the lower 

 angle of this tuberosity in front of the entrance into the orbit is 

 much sharper and more descendant, and the small notch in the 

 middle of the upper margin of the orbit is somewhat broader j 

 but the form of the entrance of the orbit is exactly the same as 

 in Orca capensis. The postorbital process also shows some dif- 



