KILLER, or °RCA, a cetacean of the dolphin family, noted for its great ferocity and voracity. The average length of the males is 20 ft., of the females, 15 feet. An extremely prominent dorsal fin is situated about two-fifths of the distance between the nose and tip of the tail. This fin is 6 ft. in height in the largest of the animals, the orca rectipinna of Cope, and has the shape of a dagger. There is also the orca ater of the same naturalist, somewhat smaller and having a much shorter fin. There has always been a want of precise classification iu this branch of the dolphin family, on account of the difficulty of capturing these fierce and powerful animals. The orca gladiator of the Atlantic is said to be a distinct species, and the fiercest of all the genus. The orca rectipinna, according to capt. Scammon, is more slender in proportion and less marked with light spots than the other species. It is almost of a jet-black above, and lighter beneath; but the smaller species are beautifully variegated, and often contrast in color like the stripes of a tiger. There is a transverse, crescentic dorsal band of white just behind the dorsal fin, which forms a prominent characteristic in two varieties of ores ater. The mouth in all the species is armed with strong, sharp, conical teeth which interlock like those of the smaller dolphins. The short-finned killers of the western coast were till recently supposed to be confined to the colder regions, but it has been found that they frequent both high and low latitudes, and capt. Scammon regards them as " marine beasts that roam over every ocean, entering bays and lagoons, where they spread terror and death among the mammoth balnas and smaller species of dol. phins, as well as pursuing seal and walrus, devouring in their marauding expeditions up swift rivers numberless salmon and other large fishes that come in their way."
Sometimes the orcas are seen in schools from 5 to 10 abreast, but more frequently go in smaller squads of less than a dozen, gliding near the surface of the water, showing noth ing but their tall dorsal fins; sometimes showing more than half the body; sometimes leaping out. The larger orcas are possessed of great power of locomotion, quickly overtaking other species of dolphins and swallowing them whole. Capt. Seammon saw an attack made by three killers upon a cow whale and her calf in a lagoon on the coasts of lower California in the spring of 1858: "The whale was of the California gray spe cies, and her young was grown to three times the bulk of the largest of the killers) engaged in the contest, which lasted for an hour or more. They made alternate assaults; upon the old whale and her offspring, finally killing the latter, which sank to the bot tom, where the water was five fathoms deep. As soon as their prize had settled to the. bottom the three orcas descended, bringing up large pieces of flesh in their mouths, whicht they devoured after coining to the surface. While gorging themselves in this wise the• old whale made her escape, leaving a track of gory water behind." He also states that; orcas have captured whales from whalemen hauling them away under the water:. Eschricht, in his Northern Species of Orca, says that they have been known tos swal low four porpoises in succession, and that 13 of these animals, together with 14 seals,. have been found in the maw of one of these killers. Among the icy regions the oreass pursue and destroy the white whale or beluga and carry off the young of the walrus.. They sometimes pursue the white whale into the bays and literally tear them to pieces,. devouring only a portion of what they destroy.