BEAKED WHALES, FAMILY ZIPHIID^ TRUE. 



29 



The inferior end of the tooth is cut off obliquely and the margin is broken by numer- 

 ous prominent rugosities. The surface of all that part of the tooth which is con- 

 tained in the alveolus and covered by the gum above it is rugose, while the part 

 above the gum is quite smooth and highly polished. 



The right tooth has the following dimensions (in straight lines) : Length of 

 anterior border, 150 mm.; length of posterior border, 107; length of superior border, 

 .54; length of inferior border, S6; average length of exposed dentine tip, 10; greatest 

 breadth of tooth, antero-posteriorl}', SI; greatest breadth of tooth, transversely, 

 15; distance from center of base of exposed portion, when in position in the 

 alveolus, to tip of dentine projection, 82; distance from center of base of portion 

 above the gum to tip of dentine projection, 70; distance from center of base 

 of portion above the gum to center of inferior margin, 76. 



The dimensions of the skulls are as follows, those of the type-specimen having 

 been revised and corrected: 



Dimensions of two slcults of 31. stejnegeri. 



Measurements. 



Total length 



Length of rostrum 



Distance from occipital condyles to distal end of maxillce. 



Breadth between centers of orbits 



Breadth between zygomatic processes 



Breadth between temporal foss:E 



Breadth between postorbital processes of frontals 



Breadth of rostrum at base (between maxillary notches) 



Breadth of rostrum at middle 



Depth of rostrum at middle 



Greatest breadth of anterior nares 



Greatest breadth of premaxillceproximally 



Greatest breadth of premaxillse in front of nares 



Length of temporal fossa 



Depth of temporal fossa 



.'Vntero-posterior length of orbit 



Breadth of foramen magnum 



Length of tympanic bulla 



Breadth of tympanic bulla 



Length of mandible 



Length of symphysis 



Distance from anterior end of mandible to alveolus 



143132 

 U.S.N.M. 

 Yaquina 



Bay, 



Oregon, 



adult. 



715 



413 



612 



309 



310 



228 



323 



172 



40 



52 



56 



130 



108 



92 



63 



96 



38 



48 



32 



610 



138 



166 



21112 



U.S.N.M. 



Bering Id. 



Type 



(1715), 



young. 



1633 

 a 325 

 567 

 279 

 278 

 212 



6 158 



44 



42+ 



54 

 118 

 109 



86 



46 



82 



39 



« Tip of rostrum lacking. 



i> The skull is much worn around the left notch and the measurement is only approximate. 



EXTERNAL FORM. 



The photograph of the head (PI. 40, fig. 4) shows that the end of the beak was 

 quite blunt, and the lower jaw quite a little longer than the upper. The superior 

 margin of the lower jaw, which is concave in front of the tooth, is strongly convex 

 and elevated at the side of it and behind it. The inferior margin of the upper jaw 



