30 BULLETIN 73, UNITED STATES NATIONAL MUSEUM. 



is Straight anteriorly, but farther back appears to be pressed upward by the tooth. 

 An examination of the skull shows that the mandible can be lowered so that the 

 teeth are below the upper jaw, but when so lowered the space between the teeth 

 and the upper jaw on each side is barely a quarter of an inch (6 mm.). With the 

 integuments in place, it is doubtful whether the mouth could be opened any wider 

 than is shown in the photograph. The convexity of the head, shape of the blow- 

 hole, position of the eye, etc., do not appear to differ materially from the same 

 characters in adults of M. bidens. 



Genus ZIPHIUS Cuvier. 



ZIPHIUS CAVIROSTRIS Cuvier. 



ZipMus caviroslris Cuvier, Oss. foss., 2d ed., vol. 5, 1823, p. 353. 

 Eyperoodon gervami Duvernoy, Ann. Sci. Nat., ser. 3, ZooL, vol. 5, 1851, p. 49. 

 Ziphiiis gcrvaisii Fischer, Nouv. Arch. Mus. Paris, vol. 3, 1867, p. 55. 

 Eyperoodon semi-junctus Cofe, Proc. Acad. Nat. Sci. Phila., 1865, p. 15. 

 Ziphius semijunclus Trve, Proc. U. S. Nat. Mus., vol. 8, 1886, p. 586. 

 Ziphius grebnitzkii Stejneger, Proc. U. S. Nat. Mus., vol. 6, 1883, p. 77. 



It has not seemed to me necessary in the present connection to attempt to cite 

 all the multitudinous names which have been given to this species, especially as 

 those zoologists most competent to judge, including Van Beneden, Flower, and 

 Turner, after detailed consideration, have concluded that but one species of Ziphius, 

 or at most two species, exist at present." 



Nearly all the skulls in European museums are assigned by the zoologists men- 

 tioned to Z. caviroslris proper, but some doubt has been entertained regarding two 

 or three European skulls, and one specimen from Argentina, described by Bur- 

 meister. These last-mentioned specimens have been thought to possibly represent 

 a second species, Z. gervaisii. The principal characters of the latter are the narrow, 

 flat premaxillse, the lack of a prominent mesirostral ossification, and small teeth. 

 From the large series of skulls in the National Museum, I am able to dispose of the 

 doubt concerning Z. gervaisii. I find that wherever the characters above men- 

 tioned occur the sex (when known) is female. There is every reason, therefore, to 

 believe that Z. gervaisii is the female of Z. caviroslris.'' I will return to this point 

 again later. 



In 1865 Cope described a species from Charleston, South Carolina, under the 

 name of Hyperoodon semijunclus. In 1886 I referred it to the genus Ziphius, but 



"See the following: 

 Turner, W.— Trans. Roy. Soc. Edinburgh, vol. 26, 1872, p. 769. 

 Flower, W. H.— Proc. Zool. Soc. London, 1876, p. 477. 

 Fischer, P. — Act. Soc. Linn. Bordeaux, vol. 35, 1881, p. 113. 

 Van Beneden, P. J. — Les Ziphioides des Mers d'Europe, 1888, p. 82. 

 6 An immature male might, of course, present the characters of the female, but in the former case 

 the teeth would be open at the roots and but slightly, if at all, coated with cement. 



