Order Cetacea. Cetaceans. 

 Family Physeteridae. Toothed Whales. 



Genus Mesoplodon (23). 



Mesoplodon mirum True. 



Mesoplodon mirum True, Smith. Misc. Coll., LX, 1913, p. i; Id. 



Proc. U. S. Nat. Mus., XLV, 1913, p. 651, pis. 52-57. 

 Type locality. Bird Island, Beaufort Harbor, North Carolina. 



Genl. Char. "Teeth at the extremity of the mandible small, 

 entirely concealed by the integument (in the adult female) . Mandibu- 

 lar symphysis one-fourth the length of the mandible. No basirostral 

 groove. External free border of the lacrymal bone one-half the length 

 of the orbit; its anterior end curved upward and appearing on the 

 superior surface of the skull where it joins the antero-external angle 

 of the frontal plate of the maxilla. Maxillary prominences short and 

 directed obliquely outward anteriorly, the extremity close to the 

 maxillary notch. Maxillary foramina behind the premaxillary fora- 

 mina. Frontal plates of maxillae approximately one-half as broad 

 as long." 



Color. Upperparts slate-black; lower parts of flanks and under- 

 parts yellowish purple, spotted with black; middle of belly darker; 

 in front of vent a grayish spot; fins slate-black like upperparts. 



Measurements. Total length, 16 feet; width at flukes, 4 ft., 8 in.; 

 tip of snout to origin of dorsal, 9 ft.; tip of snout to origin of pectoral; 

 3 ft. 8 in.; tip of snout to vent, n ft.; length of pectoral, i ft. 8 in.; 

 greatest depth of body, 3 ft. 5 in. Skull: total length, 810 mm.; 

 length of rostrum, 496; length from tip of rostrum to inferior border 

 of pterygoids, ; width across center of orbits, 325; width across 

 zygomatic processes, 375; breadth of middle of back, 60; length from 

 posterior border of maxillary foramen to end of maxillary protuberance, 

 63; length of portion of vomer visible on palate, 162; length of man- 

 dible, 668; length of symphysis, 193; greatest height of mandible 

 opposite coronoid process, 117. True, ex type in United States 

 National Museum. 



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