_Orca._[162]—Teeth about ¹²⁄₁₂, occupying nearly the whole length of the rostrum, very large and stout, with conical recurved crowns, and large roots, expanded laterally and flattened, or rather hollowed, on the anterior and posterior surfaces. Rostrum about equal in length to the cranial part of the skull, broad and flattened above, rounded in front; premaxillæ broad and rather concave in front of the nares, contracted at the middle of the rostrum, and expanding again towards the apex. Pterygoids of normal form, but not quite meeting in the middle line. Vertebræ: C 7, D 11-12, L 10, C 23; total 51 or 52. Bodies of the first and second and sometimes the third cervical vertebræ united; the rest free. Pectoral fin very large, ovate, nearly as broad as long. All the phalanges and metacarpals broader than long. General form of body robust. Dorsal fin near the middle of the back, very high and pointed. Anterior part of the head broad and depressed. The animals composing this genus are met with in almost all seas from Greenland to Tasmania, but the number of species is still uncertain, and possibly they may be all reduced to one. They are readily known, when swimming in the water, by the high, erect, falcate dorsal fin, whence their common German name of _Schwertfisch_ (Sword-fish). By English sailors they are generally known as “Grampuses” or “Killers.” They are distinguished from all their allies by their great strength and ferocity, being the only Cetaceans which habitually prey on warm-blooded animals, for, though fish form part of their food, they also attack and devour Seals, and various species of their own order, not only the smaller Porpoises and Dolphins, but even full-sized Whales, which last they combine in packs to hunt down and destroy, as Wolves do the larger Ruminants. [Illustration: FIG. 95.—The Killer Whale, or Grampus (_Orca gladiator_). From Hunter.] _Orca citoniensis_, of the Italian Pliocene, was of smaller size than the existing Killer. Teeth and periotic bones from the Suffolk Crag not improbably belong to the same species. _Pseudorca._[163]—Teeth about ¹⁰⁄₁₀. Cranial and dental characters generally like those of _Orca_, except that the roots of the teeth are cylindrical. Vertebræ: C 7, D 10, L 9, C 24; total 50. First to sixth or seventh cervical vertebræ united. Bodies of the lumbar vertebræ distinguished from those of the preceding genera by being more elongated, the length being to the width as 3 to 2. Pectoral fin of moderate size, narrow, and pointed. Dorsal fin situated near the middle of the back, of moderate size, falcate. Head in front of the blowhole high, and compressed anteriorly, the snout truncated.