90 



A very fine mandible in the Australian Museum belongs, I think, to 

 this new genus, for it is unusally " very broad on the sides, very thick 

 and solid in front"; to which I may add, and comparatively very wide 

 apart from condyle to condyle. I can, however, trace in it no radical 

 characters, beyond those I attribute to the natural results of age. 



This lower jaw presents the following particulars : Entire length of 

 ramus, 33 in. 9 lines. Teeth gg, vei 7 perfect ; anterior and posterior 

 pairs small, respectively increasing in size towards the central portion of 

 the tooth-line, where they become very large, conical, acute, and slightly 

 incurved at their tips, and towards the base flattened transversely ; sym- 

 physis in length, 8 in. ; height of ramus at coronoid process, 10 in. ; 

 length of tooth-line from tip to posterior edge of last tooth, 16 in. ; 

 posterior spread of jaw, meaured from outward edges of the condyles, 

 24 in. 4 lin. 



The owner of this formidable mandible must have possessed dimen- 

 sions in other portions of its structure equal to those entertained by 

 the huge Orca capensis described by Van Beneden and Gervais, and 

 greatly exceeded in magnitude, not only all of Dr. Gray's accredited 

 species of the genus, but that of his Ophysia pacifica. 



Where the sexes assume such widely different growths, why may not 

 the larger skull in our museum, and the smaller one of the O. pacifica 

 be fairly considered as sexual characteristics of the same species, of 

 which the individuals have been so fortunate as to reach an unusually 

 mature age. 



Inhab : North and South Pacific Ocean. 



Whatever differences of opinion (and they are great) that may exist 

 among zoologists as to the number of species, all bestow upon the 

 members of the family the qualities of vast strength, great ferocity, 

 and an insatiable appetite. Pliny, more than 1,800 years ago, recorded 

 the ferocious habits of this rapacious whale, which Linnaeus 1 , Otho 

 Eabricius, Nilsson, and other naturalists, have fully confirmed. 



From the more recent observations of reliable men, I select the fol- 

 lowing interesting accounts of the habits of the killers. Captain Holboll 

 states that, " in the year 1827 I was myself an eye-witness of a great 

 slaughter performed by these rapacious animals. A shoal of Belugas had 

 been pursued by these blood-thirsty animals into a bay in the neighbour- 

 hood of Godhavn, and were there literally torn to pieces by them. 

 Many more of the Belugas were killed than eaten, so that the Green- 

 landers, besides their own booty, got a good share of that of the killers. 

 In the year 1830, a large Krepokak (Megaptera longimana) was over- 

 powered by an Orca, in the neighbourhood of Narparsok, according to 

 the statements of the Greenlanders, and torn to pieces after it was dead. 

 Almost fifteen barrels of the blubber, floating about at the place where 

 the struggle had taken place, fell to the share of the Greenlanders. It 

 is principally the blubber that is the most coveted food of the killers, 



1 " Balaenarum Phocarumque tyrannus, quas turmatim aggreditur." 



