Mesoplodon longirostris (Cuvier *). 



Syn, Ziphius longirostris, Cuvier 2 . 

 Dioplodon becani, Gervais 3 . 

 Ziphius medilineatus, Owen 4 . 

 Dioplodon medilineatus, Gervais 9 . 



The specimens from the English Crag, described by Owen as 

 Z. medilineatus, are undoubtedly specifically identical with the 

 Belgian D. becani 8 , and the latter appears to be the same as Z. longi- 

 rostris 7 . The locality of the type rostrum of the latter (which is 

 preserved in the Paris Museum) is uncertain. 



Fie. 13. 



Mesoplodon lojiffirostris. Diagrammatic transverse section of the cranial ros- 

 trum. 13, vomer; 14, mesethmoid ; 21, maxilla; 22, preruaxilla. |. 

 (From the Mon. Pal. Soc.) 



The species is about equal in size to the existing M. australis. 

 The rostrum is long and narrow, its mesethmoid element (fig. 13) 



1 Ossemens Fossiles, 2nd ed. yol. v. pt. 1, p. 357 (1823). Ziphius. 



2 Loc. cit. 



3 Zool. et Pal. Fra^aises, 1st ed. vol. ii. Exp. No. 38, p. 2 (1848-52). 



4 Crag Cetacea (Mon. Pal. Soc.), p. 22 (1870). 

 6 Ostdographie des Cetaces, p. 422 (1868-79). 



6 See Gervais, op. cit. pp. 421-422. 



7 See Du Bus, Bull. Ac. E. Belg. ser. 2, vol. xxiv. p. 570 ; Qervais (loc. cit.} 

 had some doubt as to the identity of the two forms. 



