OF THE RED CRAG. 



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It is completely petrified, and yields on percussion the clear metallic ringing sound 

 characteristic of the Cetacean fossils from this formation ; but it is less deeply stained by 

 ferrugineous salts than is commonly seen in the fossil snouts from other SufiPolk Red 

 Crag localities. 



Species — Ziphius gibbus, Owen. Plate II, fig. 2 ; and Plate III, fig. 3. 



Amongst the fossil, as in existing, Ziphii are some species with an excessive develop- 

 ment of the 'mid-tract' in the upper surface of the rostrum. 



I propose the specific term ' pibbus' for one of the ' Red Crag' snouts, because the 

 mid-tract is not only convex transversely (PI. II, fig. 2, 14', 14'), but rises by a more 

 defined and elevated longitudinal convexity (PI. Ill, fig. 3, i4') than in the other fossil 

 species. 



In the specimen exempHfying this character — the subject of the figures cited — a smaller 

 portion of the fore pai't of the prenasal fossae (PI. II, fig. 2, 22') is included than in Z'qjUus 

 planus. Sufficient of the fore part of the ' septum narium' (ib., fig. 2, 14) is preserved to indi- 

 cate an unsymmetrical twist to the left, and also to demonstrate that such part of the bony 

 septum is absolutely thicker than in the larger existing species, Ziphius Layardi, and that 

 it is thinner both absolutely and relatively than in Ziphius angustus (PL III, fig. 2). It 

 expands, in Ziphius gibbus, immediately beyond the nostrils, and rapidly, into the ' mid- 

 tract ' (14'), which gains, with some excess on the right side, a breadth of one inch at twice 

 that distance from the nostrils, then gradually narrows to three fourths of an inch, and 

 again expands both transversely and vertically to the extent shown in the figures cited. 

 The subsidence, longitudinally, to the fractured fore part of this rostrum is more rapid 

 than the rise, and that, as it appears, without any mechanical influence of posthumous 

 abrasion (PI. Ill, fig. 3). The proportion of the upper surface of the rostrum contri- 

 buted by the narrower part of the mid-tract (14'), at the point marked by the star in fig. 3, 

 is shown in the outline of the circumference at that part (drawn with the upper part 

 downward) in PI. Ill, 14' ; the much larger proportion which, through its own expansion 

 and the subsidence of the side tracts of the premaxillaries (22), the mid-tract (14') forms at 

 the part of the rostrum marked by the star in PI. II, fig. 2, is indicated at 14', 14' in 

 the superadded outline of the transverse section at that part of the rostrum. 



The nasal processes of the premaxillaries (22', 22', fig. 2, PI. II) are perforated, each 

 by an orifice {d) relatively wider than in Ziphius Layardi (PI. I, fig. 2, rf) ; and no 

 groove is continued forward from the ' foramen naso-premaxillare' {d) in Ziphius gibbus, 

 as is the case in Ziphius planus and Ziphius Layardi. 



The commencement of the interorbital expanse of the maxillary (21, fig. 2, PI. II) in 



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