IG 



BRITISH FOSSIL CETACEA 



Gc7ius — ZiPHius, Cuvier} 



Species — ZiPiiius planus, Owen. Plate II, fig. 1. 



This species is represented by the basal part (probably third) of the rostrum, including 

 the fore part of the right (r) and left (/) prenasal channels or fossae, leading from the 

 nostrils to the ' premaxillary' grooves or canals {d,d). These concavities present the 

 same unsymmetrical twist as in Ziphius Layardi (PI. I, fig. 2, r and /), Z. plani- 

 rostris (fig. 2, 22', 22'), and Z. Cuvieri (fig. 3). The disproportionate breadth of the 

 right prenarial channel (PI. II, fig. 1, 22', r) is greater in the fossil. The correspondingly 

 bent prefrontal septum (14, u) is relatively thicker than in Z. Layardi, and is more 

 directly continued into the mid-tract (14'), which is flatter above, than in the recent 

 species, resembling in that respect Ziphiiis Cuvieri (fig. 3j. The premaxillary grooves 

 {d, d) continued forward from the fore ends of the prenasal fossse (r, l) show, at their 

 commencement, the orifice of a small canal, as in Ziphius Layardi, leading into the 

 osseous substance of the rostrum. The prenasal grooves soon subside. The interme- 

 diate prefrontal tract is continued on flattened above, not convex, as in Z. Layardi, but 

 the generic resemblance is well marked. The posterior part of the maxillaries include the 

 large anterior nervo-vascular (antorbital) foramen [b), and show the posterior beginning of 

 the ectomaxillary groove {g, g), the upper border of which is developed to form the ecto- 

 maxillary ridge (e, e) ; this speedily subsides. The superiorly flattened mid-tract (14', 14') 

 slightly expands toward the fractured fore end of the rostrum, where its lateral boundaries 

 sink into wide and shallow longitudinal channels. The worn surface of the under part of 

 this rostral fragment yields no satisfactory character. 



The upper surface of the fossil is represented of the natural size (PI. II, fig. 1), and 

 indicates a species of Ziphius larger than the Z. Layardi. The vertical diameter of the 

 rostrum, at i, is 4 inches. 



The specimen was found in the Red Crag at Shotley, Sufl"olk, and had been spht, 

 lengthwise and vertically, by a workman, the fissure extending from the right prenasal 

 fossa to the middle of the mid-tract (14', 14'). 



' Synonyms : — Epiodon, Biodon, Ileterodon, Dioplodon, Alainin, Del phinorhT/nchus, Petrorhtjnchvs, 

 Dolicfiodon, Micropterus and Micropteron, Mesoplodon, Mesodiodon, Ziphiopsis, Placoziphius, Aporotus, 

 Ziphirostrum, Rhinostodes, Berardius, Ilop/ocetus, Eucetus, Ziphiorhynchus, Choenodelphinus, Choenocetus, 

 Belemnoziphius, &c. (the mob is included in the family Rhynchoceti, Eschricht). 



