RISSO'S DOLPHIN— KILLER — PORPOISE 



2 45 



and showing a yellowish tinge. The whole body is marked irregularly with 

 light streaks, apparently due to wounds inflicted by the spines on the suckers 

 of the squids upon which this species feeds. Though a stranger to the Arctic 

 seas, this dolphin has a very wide distribution, having been found in the North 

 Atlantic, the North Sea, and the Mediterranean, as well as in the South Atlantic 

 and North Pacific. 



Still more widely distributed appears to be the killer, or grampus 

 (Orca gladiator), which is one of the largest of the group, growing to 

 a length of fully 20 feet. It is easily recognised by its striking coloration, 

 conical depressed head, and tall back-fin, as well as by its armature of powerful 

 teeth, of which there are from ten to thirteen pairs in each jaw. In colour, killers 



KUler. 



-•-•/,':-> 



THE KILLER. 



are generally black above and whitish below, the white extending in a tongue-like 

 form on to the flanks, and also as a patch above each eye. Killers are generally 

 seen in small shoals, sometimes consisting of males and females only, and sometimes 

 of individuals of both sexes and all ages. They surpass all their relatives in 

 ferocity, and their principal prey appears to be porpoises, but they often join 

 in small parties to attack the largest whales, such as the Greenland species, 

 which become so terrified by the onslaught as to make little or no attempt .at 

 escape or resistance. 



Familiar to almost all is the European porpoise (Phocosna com- 

 munis), a species dark slaty grey above and whitish below, with the 

 tail-fin reddish or yellowish. Gi^owing to a length of about 5 feet, this species 

 is characterised by the sloping head, the equality in the length of the upper and 

 lower jaws, and the large triangular back-fin placed a little in front of the middle of 



Porpoise. 



