Delphinus orca, _Cuv._ _Oss. Foss._ v. tab. 22. fig. 4 (skull). The skull very similar to that of the Cape species, but much smaller; but the beak is rather narrower, the intermaxillaries moderately broad, slightly dilated in front. Inhab. North Sea. An adult skull from the coast of Essex (361 _a_), and another without the lower jaw, are in the British Museum. These skulls of the smaller British, or, rather, European _Orca_ are distinguishable from those of _O. gladiator_ by the smaller size and the broader, rounder nose—and from the skulls of the Cape-of-Good-Hope species by being of a much smaller species, and having a depressed crown of the head. I believe the skull figured under the name of _Delphinus orca_ by Cuvier, Oss. Foss. vol. v. tab. 22. figs. 3, 4, represents this species, from the form of the beak and the narrowness of the occiput: this figure has been copied by various British and other authors. 1. Orca gladiator, var. arcticus (O. Eschrichtii), _Gervais_, _Ostéogr. Cét._ t. 47. fig. 3. Inhab. Faroe Islands. 2. Orca gladiator, var. europæus, _Gervais_, _Ostéogr. Cét._ t. 47. f. 4. Orca gladiator, _Gervais_, _l. c._ t. 48. f. 1. Inhab. the Atlantic. Skull about 40 inches long. 3. Orca gladiator, var. europæus, _Van Beneden & Gervais_, _Ostéogr. Cét._ t. 47. f. 5. Delphinus orca, _Gervais_, _Zool. et Paléont. Française_, t. 37. f. 3, 4. Inhab. Mediterranean, Cette. Skull about 22 inches long. It is about the same size as the _Orca_ from Algoa Bay; but the brain-cavity is rather broader and the beak is not so acute in front. Gervais, in the ‘Zoology and Paleontology of France,’ figures the skull of a young _Delphinus orca_, taken on the coast of Cette, which is now in the Museum of Paris. It appears to belong to this species; or it may be that the _Orca_ of the Mediterranean does not grow to the usual size; or, again, it may be of a different species; for the skull is only fifty-eight centimetres long and thirty broad. 5. Orca magellanica. Orca magellanica, _Burmeister_, _Ann. & Mag. Nat. Hist._ ser. 3. xviii. p. 101, t. 9. f. 5; _An. Mus. Publ. de Buenos Ayres_, i. p. 373, tab. 22; _Gray_, _Synops. Whales & Dolph._ p. 8; _P. Z. S._ 1870, p. 76. Inhab. Patagonia. Mus. Buenos Ayres. This species, according to the figure, is very like _Orca latirostris_. 6. Orca tasmanica. Orca gladiator, var. australis, _Gervais_, _Ostéogr. Cét._ t. 47. fig. 1. Inhab. Tasmania. Skull about 32 inches long. 7. Orca rectipinna. Orca rectipinna, _Cope_, _Proc. Acad. Nat. Sci. Philad._ 1869, p. 12. No white spot behind eye. Inhab. California. 8. Orca atra. Orca ater, _Cope_, _l. c._ 1869, p. 12. Black above and below, with white spot behind eye. Inhab. Oregon, Aleutian Islands.