16 HYPEROODON. ZIPHIUS. 



maxillae, particularlj' on the right side. At base of rostrum are high 

 longitudinal crests on the maxills approximate in middle line and 

 extending backward nearly to the nares. Cervical vertebree coalesced. 

 Vertebrae 45. 



23. rostratus. {Balcend), Mull. Zool. Dan. Prodr., 1776, p. 7. 



biiientatus, Bonn. C^tol., 1789, p. 25. 



hutskopf, Bonn. Cetol., 1789, p. 25. 



anarnacus, Desm. Mamm., 1820, p. 550, No. 780. 



hunteri, Desm. Mamm., 1820, p. 520, No. 782. 



latifrons, Graj', Zool. Erebus and Terror, 1846, p. 27, pi. 4. 



hyperobdon, Schleg. Zoogd. Nederl., 1870, p. 94, pi. 18. 



Geogr. Distr. North Atlantic, Davis Straits, Hudson Straits. 



Genl. Char. Contour of head, rounded, high above the beak, 

 and descending abruptly to it anteriorly. In old males the anterior 

 part of the head resembles a flat disc-like surface nearly covering or 

 burying the beak and nearly at right angles to the line of the back. 

 Other characters those of the genus. 



Color. Old Adult. Yellowish, anterior part of head white, and a 

 white band around the neck; beneath grayish white. Young, black; 

 mature animals, light brown. 



Measurements. Total length 30 feet, 20 in circumference. 



13. Ziphius. 



1—1 

 Ziphius. Cuv. Oss. Foss., 1823, 2d ed., v, p. 352. Type Z. caviros- 

 tris, Cuv. 



Aliama. Gray, Proc. Zool. Soc, 1864, p. 242. 



Petrorhynchus. Gray, Proc. Zool. Soc, 1865, p. 524. 



Ziphiorhynchus. Burm. Ann. Mag. Nat. Hist., 1866, p. 94. 



On either side of the mandible at anterior end is a single conical 

 tooth, directed upwards and forwards. Rostrum triangular, tapering 

 from base to apex; edges of maxillae at base of rostrum raised into 

 roughened tuberosities. " Premaxillae immediately in front of and at 

 the sides of the nares expanded, hollowed and with elevated lateral 

 margins, the posterior ends rising to the vertex and curving forwards, 

 the right being considerably more elevated than the left; the conjoint 

 nasals forming a strongly pronounced symmetrical eminence at the 

 top of the cranium, projecting forwards over the nares, flat above, 

 most prominent and rounded in the middle line in front, and sepa- 

 rated by a notch on each side from the premaxillae. Anteorbital 

 notch not distinct." (Flower.) Vertebrae, 49, the three anterior cer- 

 vicals united. 



