OF THE RED CRAG. 



3 



work cited, the blow-hole is single, transversely crescentic, with the horns forward ; 

 there is a small but rather high falcate dorsal fin, the pectorals are small and placed 

 low, the caudal broadly and terminally emarginate.^ 



The rostrum in Ziphius, as demonstrated in the skulls of the existing species above 

 described, is mainly composed of the maxillaries and premaxillaries ; but it likewise 

 includes at the medial line, along a greater or less extent from the base, the prefrontal 

 and the vomer, while at its base are parts of the palatines and pterygoids. 



For a right use of a generic name it is requisite, in case of doubt, to refer to the speci- 

 men or specimens of species on which the genus has been founded, called 'type- 

 specimens' by those naturalists who use the word 'type' in that sense. The genus 

 ZipJdus was defined by Cuvier from characters afforded by more or less mutilated 

 skulls of three or more species. They Avere mainly derived from the least mutilated 

 specimen, which had been found by a peasant on the sea-shore (" sur le bord 

 de la plage") between the village of Fos and the embouchure of Galegeon, in the 

 Department of the " Bouches-du- Rhone," near the canal leading from the marsh of 

 ' I'Estomac ' to the sea.^ The occiput and most of the 

 cranial cavity were wanting; but the specimen showed 

 the temporal fossae with the orbits and interorbital 

 expanse of bone, including the nostrils and the whole 

 of the rostrum, which was edentulous. It is figured 

 in the 'Ossemens Fossiles,' torn, v, pt. 1, pi. xxvii, 

 fig. 3 (I the nat. size). I reproduce in the cut, fig. 1, 

 the original figure of part of this specimen on a larger 

 scale, given by Prof. Geuvais, in his ' Zoologie et 

 Paleontologie franpaises/ 4to, pi. xxxviii, fig. 2. These 

 figures show that the premaxillaries (22) forming the 

 end and upper part of the sides of the rostrum 

 expand as they rise ('22)> ciu'ving outward and up- 

 ward, and inclining forward at their summits (22") 

 to support a pair of small massive nasals (15) 

 wedged in grooves between them : the expanding 

 nasal plates of the premaxillaries bound or form the 



lateral walls of the cavity (prenasal fossa), into which opens posteriorly the upper outlet of 

 the nostrils, the septum of which (14) extends forward, bisecting in part the prenasal fossa. 

 The premaxillary wall or ridge dividing this fossa (22') from the maxillary (21') is represented 

 on the left side of Cuvier's fig. at 0, ; the rostral part of the premaxillary (22, fig. 1) is marked 

 y in the same figure. The maxillaries (21, fig. 1, pi. xxvii, fig. 3, e, e,f, in the ' Ossem. Foss.') 



1 As in Ziphius micropterus, 'Memoires de 1' Academic Royalc de Bruxelles,' tome xii, pi. i; and in 

 Ziphius patachonichus, ' Anales del Museo Publico de Buenos Ayres,' torn, i, pi. xv. 



^ 'Ossem. Foss.,' torn, cit., p. 150. 



Ziphius cavirostris, Ci 



