Dr. Burmeister considered it _O. falklandica_ of Shaw; and Mr. Allen (Bull. Mus. Comp. Zool. vol. ii. p. 13) agrees in this opinion; but further on (p. 15) he observes that both Dr. Gray and Dr. Murie have “evidently overlooked the fact that Dr. Peters expressly states that _O. Philippii_ has a _thick under-fur_, whereas both the _O. Stelleri_ and the _O. Hookeri_ are true _hair_ Seals.” But, in fact, this statement is a mistake as regards me; I never said that _O. Philippii_ was the same as _O. Stelleri_, but only that its skull was most nearly allied to it, which I still maintain. * * * * * _Antarctic Ocean and South Seas._ Otaria jubata. _S. America and islands._ Phocarctos Hookeri. Arctocephalus nigrescens. A. falklandicus. Arctophoca Philippii. _S. America._ Arctocephalus antarcticus. _Africa._ A. nivosus. _Africa._ A. cinereus. _Australia._ A. Forsteri. _New Zealand._ Neophoca lobata. _Australia._ _North Pacific and West Arctic Ocean._ Callorhinus ursinus. _West coast of America._ Zalophus Gilliespii. _West coast of America and Japan?_ Eumetopias Stelleri. _West coast of America._ Order CETACEA. Teeth all similar, conical, sometimes not developed. Palate often furnished with transverse plates of baleen or whalebone. Body fish-shaped, smooth, bald. Limbs clawless; fore limbs fin-shaped; hinder united, forming a forked horizontal fin. Nostrils enlarged into blowers. Teats two, inguinal.—Carnivorous. They may be divided by the form of the pectoral fin, thus:— I. _Pectoral fin broad, truncated or rounded at the end; fingers 5, shorter than the arm-bones, subequal, gradually shorter in the series._—BALÆNIDÆ, CATODONTIDÆ, SUSOIDEA, ORCADÆ, BELUGIDÆ, PONTOPORIADÆ, HYPEROODONTIDÆ, EPIODONTIDÆ, ZIPHIIDÆ. II. _Pectoral fin elongate, obliquely truncated on the inner side; fingers 5, elongate, longer than the arm-bones, the second and third much longer than the rest._—INIIDÆ, DELPHINIDÆ, GRAMPIDÆ, GLOBIOCEPHALIDÆ. III. _Pectoral fin elongate, truncated on the inner side; fingers 4, subequal, more or less elongate._—AGAPHÆLIDÆ, MEGAPTERIDÆ, PHYSALIDÆ, BALÆNOPTERIDÆ. By the adhesion or non-adhesion of the cervical vertebræ, thus:— 1. Atlas distinct, the other six cervical vertebræ united by their bodies and spines into a single mass. _Mysticetes._ _Denticetes._ CATODONTIDÆ. GRAMPIDÆ. 2. Atlas and cervical vertebræ all united into one solid mass. BALÆNIDÆ. BALÆNOPTERIDÆ. PHYSETERIDÆ. HYPEROODONTIDÆ (?) ZIPHIIDÆ. 3. The atlas, axis, and generally one or two other vertebræ united; the hinder ones sometimes free. MEGAPTERIDÆ. EPIODONTIDÆ. ? ZIPHIIDÆ. DELPHINIDÆ. GLOBIOCEPHALIDÆ. ORCADÆ. 4. Atlas and the other cervical vertebræ entirely free. PHYSALIDÆ. AGAPHELIDÆ. PLATANISTIDÆ. INIIDÆ. PONTOPORIADÆ. BELUGIDÆ. Section I. MYSTICETE (_cf._ p. 57).