g4 BULLETIN 73, UNITED STATES NATIONAL MUSEUM. 



Plate 7. 



Fig. 1. Mesoplodon hukns. Skull. Nantucket, Massachusetts. Female, adult. Mus. Comp. Zool. 

 No. 1727. Lateral aspect. } nat. size. 

 Tip of beak, left pterygoid and malar defective. 

 2. Mesoplodon densirostriif Skull. Annisquam, Massachusetts. Female, young. Boston Soc. Nat. 

 Hist. Lateral aspect. \ nat. size. 

 Distal portion of beak defective and warped. 



Plate 8. 



FiQ. 1. Mesoplodon europxus. Skull. Atlantic City, New Jersey. Male, young. Cat. No. 23346, 

 U.S.N.M. Lateral aspect. About i nat. size. 

 2. Mesoplodon curopn'us. Skull. North Long Branch, New Jersey. Female, adult. Mus. Comp. 

 Zool. Lateral aspect. About J nat. size. 

 Distal portion of beak lacking. , 



Plate 9. 



Fig. I. Mesoplodon stejiiegeri. Type-skull. Bering Island. Immature. Cat. No. 21II2, U.S.N.M. 

 Lateral aspect. About J nat. size. 

 Premaxilla\ maxilhc, frontals, zygomatic process, etc., defective. On account of these defects 

 and the immaturity of the individual the forward inclination of the supraoccipital is much 

 greater than in the skull shown in fig. 2. 

 2. Mesoplodon stepiegeri. Skull. Yaquina Bay, Oregon. Adult. Cat. No. 143132, U.S.N.M. 

 Lateral aspect. J nat. size. 

 Proximal end of premaxilKe defective. 



Plate 10. 

 Skulls of Mesoplodon. 



Fig. 1. Mesoplodon bidens. Nantucket, Massachusetts. 



2. Mesoplodon densirostris? Annisquam, Massachusetts. 



3. Mesoplodon europseus. Atlantic City, New Jersey. 



4. Mesoplodon europseus, North Long Branch, New Jersey. 



5. Mesoplodon stejnegeri. Type-skull. Bering Island. 



6. Mesoplodon stejnegeri . Yaquina Bay, Oregon. 

 Posterior aspect. All figures i nat. size. 



Plate 11. 



Mandibles of Mesoplodon. 



Figs. 1, 2, and 5. Mesoplodon bidens. Nantucket, Massachusetts. 

 3 and 6. Mesoplodon europieus. Atlantic City, New Jersey. 

 4. Mesoplodon stejnegeri. Yaquina Bay, Oregon. 

 All figures ^ nat. size. 



Plate 12. 



Fig. 1. Mesoplodon stejnegeri. Yaquina Bay, Oregon. Mandible and tooth. J nat. size. 



2. The same. Left mandibular tooth. Outer surface. 



3. The same. Right mandibular tooth. Inner surface. 

 All figures a little more than j nat. size. 



