OF THE RED CRAG. 



19 



Species — Ziphius angustus. 



ZiPHiDs ANGUSTUS, Owen. Plate III, figs. 1 and 2. 



The snout on which a species of Ziphius is indicated by the above name exhibits a 

 development transversely and vertically of the prefrontal mid-tract (14', 14') similar to that 

 in the foregoing species, but it is not identical; the convex mid-tract is relatively narrower, 

 as is the rostrum itself, in ZipJdtis angustus, and the narrower part of the tract, after its 

 slight hinder expansion, is of greater longitudinal extent before its second or anterior 

 expansion. The whole rostrum is more slender, as is indicated by the contour of the 

 transverse section given in PI. Ill, at the part marked with the star in figs. 1 and 2, 

 which corresponds with the part of the rostrum similarly marked in ZipJiius gibhm (ib., 

 fig. 3). Moreover, the ectolateral maxillary ridge (ib., fig. I, e, e') is longer, extending 

 further forward upon the side of the rostrum, and subsiding more gradually. 



The premaxillary foramina {d, d, fig. 2) are as large as in ZipMus gihhus. Only 

 the inner walls of the maxillary foramina (6, 6, 2 1 , fig. 2) remain ; they show them to be 

 on the same transverse line as d, d, but to be nearer thereto, indicative of a continuance of 

 the slender character of the snout to this commencement of the maxillary platform. The 

 ectomaxillary groove (ib., fig. 1, eg) is narrow, and extends forward, descending, as in 

 Ziphius gibhus ; but its lower border begins to swell outward (e', 21, fig. 1) as it gets toward 

 the fore end of the present fragment, as in Ziphius Layardi, indicating that one half or 

 more of the rostrum may be wanting in the present specimen. The sides of the pterygo- 

 palatine ridge are slightly concave in Ziphius angustus, at the part where they show a 

 moderate convexity in Ziphius gihhus, and it is improbable that this difierence can have 

 been caused by posthumous abrasion. 



The specimen described is figured of the natural size in the two views given in 

 PI. Ill, figs. 1 and 2. 



The density of the bony texture of the fractured fore part of the snout closely accords 

 with that of the same part in the recent Ziphius Layardi, and suggests an application, by 

 the living animal, of the snout analogous to that of the similar rapier- like rostral weapon in 

 the Sword-fish [Histiophorus^. 



