68 CETACEA. 



Mesoplodon longirostris (Ciivier ^). 



Syn, Ziphius longirostris, Cuvier ^. 

 Dioplodon becani, Gervais ^. 

 Ziphius medilineatus, Owen*. 

 Dioplodon medilineatus , Gervais 5. 



The specimens from the English Crag, described by Owen as 

 Z. medilineatus, are undoubtedly specifically identical with the 

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

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

 preserved in the Paris Museum) is uncertain. 



Ficr. 18. 



Mesoplodon longirostris. — Diagrammatic transverse section of the cranial ros- 

 trum. 13, vomer; 14, mesetbmoid ; 21, maxilla; 22, premaxilla. \. 

 (From the Men. 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) 



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

 ^ Log. cit. 



3 Zool. et Pa], Fran9aises, Ist ed. vol. ii. Exp. No. 38, p. 2 (1848-52). 



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

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

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



'^ See Du Bus, Eull. Ac. R. Belg. ser. 2, vol. xxiv. p. 570 ; Gervais {loc. cit.) 

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



