18 



i^m'nsiT FOSSIL cetacea 



Ziphius gihhus shows the nervo-vascular foramen (5, h) on nearly the same transverse line 

 as d, d; the downward and backward direction of the canal leading therefrom to the 

 common entorbital foramen^ is shown at d, fig. 3, PI. III. 



The pterygoid alae (PI. Ill, fig. 3, 24) would seem to be directly applied to the under 

 part of these maxillary expansions, and not to be separated therefrom by the fissure seen 

 in Ziphius Layardi (PI. I, fig. 1, between 21' and 24') ; but on this point the abraded 

 condition of the hinder end of the rostrum makes it unsafe to insist. It appears certain 

 that the representative of the ectomaxillary ridge (PI. II, fig. 2, 21. ..e, and PI. Ill, 

 fig. 3, e, eg) is much thinner vertically than in Ziphius Layardi^ and more rapidly sub- 

 sides as it advances forward upon the side of the base of the rostrum. A narrow ecto- 

 maxillary groove (PI. Ill, fig. 3, eg) is continued forward from the point of subsidence 

 to the broken end of the snout, gradually sinking toward the lower part of the snout, as 

 in Ziphius Layardi. No sutural evidence of the proportions of the maxillary and preraax- 

 illary bones remains upon the sides of the rostrum under description. Neither, though 

 there be an indication of the structure, can it be certainly affirmed that the veritable 

 vomer contributes any proportion of the smooth, transversely convex under surface of the 

 rostrum, the curves of which, in transverse section, are indicated in the outlines taken at 

 the two points marked in Pis. II and III. 



A medial linear suture marks the meeting of the palatal plates of the maxillaries, 

 anterior to the palatine bones, as in Ziphius Layardi (PI. I, fig. 3, 20), and this line can 

 be traced inclining to the right side, as in the right vomero-maxillary suture in Z. Layardi, 

 but the left one is obliterated, if it existed, in Ziphius gihhus. The medial plates of the 

 pterygoids have met and been in contact for a greater extent in Ziphius gihhus than in 

 Ziphius Layardi, descending to form a deep median angular ridge, to the fore part of 

 which the palatines seem to have contributed some share. But here, again, the 

 state of abrasion affects the utility of further attempts to specify structural characters. 



Sufficient, however, of the present rostrum has defied the effects of long ages of surf- 

 movements, through the degree of petrifaction undergone before dislodgment from its 

 original burial-bed, to justify the specific distinction attempted to be pointed out, and, at 

 all events, to afford means of comparison which may lead to a reference of other specimens 

 of Crag- whale-snouts to the Ziphius gihhus. 



1 Shown at d, fig. 2, pi. 13, ' Indian Cetacea,' loc. cit., in Euphysetes simus. 



