PHYSETEEIDiB. 69 



appearing largely on the superior surface and exhibiting a distinct 

 median longitudinal groove ; at its hinder extremity the mesethmoid 

 is flat, and does not project above the plane of the adjacent bones, 

 while the antero-posterior gibbosity near the middle is compara- 

 tively small ; in advance of the gibbosity the rostrum is slender, and 

 presents a subcircular cross section. 



Hah. Europe (Belgium, England, and Italy ^). 



All the following specimens are from the Red Crag of Suffolk. 



37722. The hinder part of the cranial rostrum. This specimen is 

 {Fig.) the type of Z. medilineatus, and is figured by Owen in 

 the ' Crag Cetacea' (Mon. Pal. Soc), pi. iv. fig. 3. 



{From the Saul Collection.) Purchased, 1863. 



46924. Cast of the cranial rostrum, of which the original was obtained 

 from Woodbridge. This specimen agrees very closely with 

 the preceding, although the median groove has been partly 

 obliterated by rolling. The gibbosity in the middle of 

 the rostrum is but slightly marked, and the anterior ex- 

 tremity subcylindrical. Purchased, 1875. 



M. 1612. A very similar cranial rostrum ; from Eelixstowe. The 

 median groove extends over nearly two thirds the length 

 of the specimen. This and the preceding specimen appear 

 indistinguishable from the type rostrum of P. hecani, 

 figured by Gervais in the ' Zool. et Pal. Pran9aises,' 

 pi. xxxviii. fig. 4, and in the ' Osteographie des Cetaces,' 

 pi. xxvii. fig. 7. 



Presented hy C. Westendarp, Esq., 1884. 



M. 1613. The anterior extremity of the rostrum ; from Eelixstowe. 

 Presented hy C. Westendarp, Esq., 1884. 



46680. The cranial rostrum ; from Woodbridge. This specimen is 

 indistinguishable from No. M. 1612. Purchased, 1875. 



42514. The hinder part of the cranial rostrum ; from Sutton. 



Purchased, 1871. 



30272. The hinder part of a small cranial rostrum, probably belong- 

 ing to this species. Purchased, 1855. 



^ See Capellini, Mem. Ac. Sci. 1st. Bologna, ser. 4, vol. yi. p. 298 (1885). 



