PORPOISES AND DOLPHINS. 51 



The Killer, or Grampus. 



Genus Orca. 



One of the largest, and at the same time the most ferocious, of all the dolphin 



family is the killer, or killer whale, frequently also known as the grampus 



(Orca gladiator). It is characterised as a genus by its large size, and the conical 



and depressed head, devoid of a beak. The back-tin is of great length, especially 



in the males; and the nippers are large and 



broadly ovate. The teeth (as shown in our 



figure) are comparatively few in number, varying 



from ten to thirteen on each Bide of the jaws. 



and are much larger than in any dolphins yet 



noticed, being often an inch or more in diameter, 



and having an oval-section. The coloration is 



striking, the upper-parts and tins being black, THE KIRST SIX UPPEH TEETH 0F THE ^ 



while the lower jaw, chest, ami under-parts are (From Sir W. H. Flower.) 



whitish. The white area of the under-parts doe.-, 



not, however, extend to the flukes, but ends posteriorly in a trident, of which the 



lateral and shorter prongs extend obliquely upwards on the flanks. There is a 



large white streak above and behind the eye: and frequently at least a purple 



crescentic area extends across the back behind the tin. The killer attains a length 



of at least 20 feet 



In spite of many nominal species having been recognised, there 

 Distribution. l J l .... 



can be little doubt that the killer has a cosmopolitan distribution : 



ranging from Greenland in the north to the coasts of Australia in the south. 



Although chiefly keeping to the open sea, killers occasionally ascend tidal rivers; 



and three specimens were observed in the Thames in the spring of 1890. These 



individuals entered the river during the night, and on the following morning were 



seen swimming up and down the reach between Battersea and Chelsea Bridges. 



After continuing there for several hours, they at length headed for the sea, which 



they probably reached, as there is no record of their having been attacked. 



When at sea, killers may always be recognised by their tall and 



nearly vertical back-fin. They generally associate in small parties : 



and subsist not only on fish, but likewise on the flesh of other members of their 



own order, as well as on that of seals. Captain Scammon writes that " the killers 



exhibit a boldness and cunning peculiar to their carnivorous propensities. At 



times they are seen in schools, undulating over the waves, — two, three, six, or eight 



abreast, — and, with the long, pointed fins above their arched backs, together with 



their varied marks and colours, they present a pleasing and somewhat military 



aspect. But generally they go in small squads, — less than a dozen, — alternately 



showing themselves above the surface of the water, or gliding just below, when 



nothing will be visible but their projecting dorsals ; or they disport themselves by 



rolling, tumbling, and leaping nearly out of the water, or cutting various antics 



with their flukes. At such times, they usually move rapidly over the surface of 



the sea, and soon disappear in the distance." It appears that at times both the 



