NORTH ATLANTIC RIGHT WHALE. 



121 



length of nasals along inner border 

 Breadth of nasals anteriorly 

 " " " posteriorly 

 Length of maxillary, axial 



on curve of superior external border 

 " " intermaxillary 



along dorsal convexity 



Breadth of skull at orbital processes of frontal 

 Breadth of skull at Zygomatic processes 



" " " " mastoid processes 

 (Ireatcst breadth of occipital bone 

 Transverse breadth of occipital condyles 

 Antero-posterior " " 

 Length of mandible, axial 



along external curvature 

 Greatest depth 



Transverse diameter of condyle 

 \'ertieal " " " 



The skull of Eubalaena is very characteristic in appearance and highly specialized for the 

 support of the long and narrow plates of baleen through the narrowness of its rostral portion, 

 especially of the maxillary bones from which these blades depend. In addition to the great 

 Literal reduction of these bones, the entire rostrum is strongly arched in side view to accommo- 

 date the long baleen plates. This portion of the skull, as seen from the above table is more 

 than two thirds of the total length. The intermaxillaries project somewhat beyond the tips of 

 the more lateral maxillary bones, and the nasals are enclosed between their proximal ends at 

 the base of the rostrum. The nasals are each deeply notched at their free end and form the 

 posterior boundary of the nasal opening. A narrow tongue of the maxillary and the frontal 

 me are produced postero-laterally and meet a lateral extension of the squamosal bone to form 

 the eye socket, which is further defined by the short thick jugal forming the ventral half of the 

 orbit. The occipital portion of the skull is broad and rounded in outline. Viewed from above 

 I he lower jaws bow widely out on either side to support the thick and massive lower lips. They 

 extend slightly beyond the upper jaw. The condyles are large and round, but the coronoid 

 process, though present in the Balaenopterae, is lacking, a further mark of specialization. A 

 canal is present on the internal side at the base, for the mandibular branch of the facial 

 nerve. 



The Provincetown specimen of 1864 had 56 vertebrae, namely, cervicals 7, dorsals 14, 

 lumbars 11, caudals 24. Andrews (1908, p. 176) found the same formula in two Long Island 

 specimens, exept that one had only 23 caudals. True (1904) records a Long Island speci- 

 men in which the formula was C. 7, D. 14, L. 10, Ca. 26 = 57, but the other formula is the more 

 isual. 



