NORTHERN SPECIES OF ORCA. 169 



11.^ 



After this more recent information, the doubts expressed by Scoresby and Bennet, as to 

 whether the Orcas really persecute marine mammalia or not, must be considered as completely 

 removed. The killers must be called carnivorous animals, in the strictest sense of the word, 

 and as such they stand so isolated in the order of Cetaceans that they deserve, if only for that 

 very reason, to form not only a genus by themselves, but a peculiar group or family among 

 the toothed-whales. 



Nor will it be difficult to point out the characters of this peculiar group in the form of 

 their bodies, nay even to fix them so distinctly, that it can hardly be doubted in any case, whether 

 a Cetacean, be it swimming in the sea, or only presenting single portions of its body for examina- 

 tion, does belong to this group or not. 



When swimming about in the sea, every Orca may always easily be recognised by its high 

 dorsal fin, for even in the low-finned ones this is still one tenth of the entire length of the animal, 

 and it is hardly ever found so high in any other Cetacean. The kiUers never move about in great 

 shoals like those of the ca'ing-whales {Globiocephalus) or the species of Grampus, but only twelve 

 or sixteen individuals together, and these are said to be regularly arranged in several rows 

 during their wanderings. As soon as the whole body of a killer appears, it may be known at 

 the first glance, by its parti-coloured appearance, which seems to be common to all the species, 

 for not only does the white or cream-coloured tint of the belly form a striking contrast to the 

 jet black colour of the back, but the sides are also marked with large symmetrical figures in these 

 two colours. 



These characters, however well they may serve as leading hints in identifying an in- 

 dividual, may, nevertheless, be considered as not very essential ; the same may be said about 

 the considerable size, though in this respect, the killers surpass all other Cetaceans with teeth 

 in both jaws, but not about the extremely powerful structure of their bodies, by which they are 

 distinguished from all others, both as to the whole frame of the body, and as to every one of its 

 separate parts. Although very fat animals, yet we do not find in them that peculiar adipose 

 swelling on the head, by which the teutophagous Cetaceans (the cachalots, the bottleheads, and 

 the ca'ing-whales) are characterised, and though large and powerfully made, they have nothing 

 of the clumsiness of these. As to the fins, it is not only the high dorsal fin that distin- 

 ' guishes them from all other toothed-whales, but also the extraordinarily large pectoral fins. In 

 the ca'ing-whales, the latter are, indeed, considerably longer, and this seems to be the 

 case with certain species of the genus Grampus, but at the same time they are always very 



^ This second and last section of Professor Eschricht's memoir was not yet published, 

 when death suddenly terminated his scientific labours. The manuscript found among his papers, but 

 unfortunately still unfinished, was printed in the Proceedings of the Royal Danish Society of Sciences, 

 forJ862 (pp.234 — 264) under the superintendence of Professor Steenstrup. 



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