Genus MESOPLODON Gervais. MESOPLODON BIDENS (Sowerby). North Atlantic Ocean; northern France to Norway and Sweden; Nantucket Island, Massachusetts. MESOPLODON EUROPÆUS (Gervais). North Atlantic Ocean; English Channel; New Jersey. MESOPLODON GRAYI Haast. New Zealand and Chatham Islands; Bahia Nueva, Patagonia (Moreno). MESOPLODON DENSIROSTRIS (Blainville). Indian Ocean and South Seas; Lord Howe Island; Seychelles Islands; South Africa; Massachusetts(?). MESOPLODON HECTORI (Gray). New Zealand. MESOPLODON BOWDOINI Andrews. New Zealand. MESOPLODON LAYARDI (Gray). South Seas; New Zealand, Chatham Islands; Australia; Cape of Good Hope. MESOPLODON STEJNEGERI True. North Pacific Ocean; Bering Island and Oregon. Genus ZIPHIUS Cuvier. ZIPHIUS CAVIROSTRIS Cuvier. Cosmopolitan. Genus BERARDIUS Duvernoy. BERARDIUS ARNUXII Duvernoy. New Zealand. BERARDIUS BAIRDII Stejneger. North Pacific Ocean; Bering Island and St. George Island, Bering Sea, to Kiska Harbor, Alaska, and Centerville, California. Genus HYPEROÖDON Lacépède. HYPEROÖDON AMPULLATUS Forster. Arctic and North Atlantic oceans; Mediterranean Sea; southern France; New York Bay, Newport, Rhode Island, and Cape Cod, Massachusetts. HYPEROÖDON PLANIFRONS Flower. Indian and Pacific oceans; Lewis Island, Australia; Province of Buenos Ayres, Argentina, and territories of Chubut and Santa Cruz, Patagonia. FOOTNOTES [1]As this species is well known, the skeleton is not described in this paper. [2]Amer. Nat., vol. 40, 1906, p. 366. [3]Proc. Boston Soc. Nat. Hist., vol. 11, 1866-68, p. 318. [4]Idem, vol. 29, 1899, p. 9. [5]Amer. Nat., vol. 40, 1906, p. 357. [6]Proc. Boston Soc. Nat. Hist., vol. 11, 1866-68, p. 318. [7]One of the teeth of Sowerby’s specimen is figured by Lankester in Trans. Roy. Micr. Soc., new ser., vol. 15, 1867, pl. 5, figs. 1, 2. [8]Bull. Mus. Comp. Zoöl., vol. 1, 1869, p. 205. [9]Trans. Roy. Soc. Edinburgh, vol. 26, 1872, p. 771. [10]Zoologist, ser. 3, vol. 17, Feb., 1893, p. 42; Ann. and Mag. Nat. Hist., ser. 6, vol. 11, 1893, p. 275. [11]Trans. Linn. Soc. London, vol. 7, 1804, p. 310. [12]Bergens Mus. Aarb., 1904, no. 3. [13]The external margin is broken at this point. [14]Ann. and Mag. Nat. Hist., ser. 6, vol. 11, 1893, p. 277. [15]Bergens Mus. Aarb., 1904, No. 3, pp. 27, 28. [16]Trans. Zoöl. Soc. London, vol. 10, 1878, p. 418. [17]Second ed., plate 40, fig. 4. [18]Plate 25, fig. 2. [19]Amer. Nat., vol. 40, 1896, pp. 363-370, fig. 3 (tooth, nat. size); fig. 4 (sternum). [20]Bull. Soc. Linn. Normandie, vol. 10, 1866, p. 177. [21]Bull. Acad. Roy. Belgique, vol. 41, 1888, p. 117. [22]Amer. Nat., vol. 40, 1906, p. 359. [23]Ostéographie, plate 24.