M Manigault, G. E., 35 Mearns, Dr. E. A., 32 L. di Z., 32 _Mesoplodon_, 3 _Mesoplodon bidens_, 2, 3, 4, 11 distribution of, 76 external dimensions of, 23 from Nantucket, Mass., 2, 3, 4 mandible of, 6 phalangeal formula of, 18 skull of, 4 skull, dimensions of, 8, 15 teeth of, 6 vertebral formula of, 15 _Mesoplodon bowdoini_, 3 distribution of, 77 _Mesoplodon densirostris_, 2, 9, 28 description of exterior of, 10 distribution of, 76 earbones of, 83 external dimensions of, 23 from Annisquam, Mass., 2, 3, 4 skull, dimensions of, 8 _Mesoplodon europæus_, 2, 11 color of, 22 distribution of, 76 external characters of, 21 external dimensions of, 20, 23 first record of, 11 from Atlantic City, N. J., 2, 3, 11 history of, 20 from North Long Branch, N. J., 2, 3, 11 lungs of, 22 mandible of, 14 pectoral limb of, 18 phalangeal formula of, 18 ribs of, 17 scapula of, 18 skeleton, dimensions of, 18 skull of, 13 specific characters of, 12 sternum of, 18 stomach of, 22 teeth of, 15 tongue of, 22 type-skull of, description of, by L. Brasil, 24 Van Beneden’s opinion regarding, 12 vertebræ of, 15, 16 vertebral formula of, 15 _Mesoplodon grayi_, 3 distribution of, 76 _Mesoplodon hectori_, distribution of, 77 _Mesoplodon layardi_, 3 distribution of, 77 teeth of, 28 _Mesoplodon stejnegeri_, 2, 24 distribution of, 77 earbones of, 83 external characters of, 29 from Bering Island, 1, 3 from Oregon, 1, 2, 3 mandible of, 28 skull of, 25 skull, dimensions of, 29 teeth of, 28 teeth, dimensions of, 29 Museum of Comparative Zoölogy, 2, 3, 76 O Oregon, _Mesoplodon stejnegeri_ from, 1, 3 P _Physeter bidens_, 4 _planifrons_ (_Hyperoödon_), 77 Pla-un, 66 Pribilof Islands, _Berardius_ from, 1 R Ring, J. H., 63 _rostrata_ (_Balæna_), 76 _rostratum_ (_Hyperoödon_), 76 S St. George Island, Alaska, _Berardius_ from, 1 Scollick, J. W., 32 _semijunctus_ (_Hyperoödon_), 30 (_Ziphius_), 30 _seychellensis_ (_Ziphius_), 9 Soderman, Captain, 32 _sowerbensis_ (_Delphinus_), 4 _sowerbyi_ (_Delphinus_), 4 Stejneger, Leonhard, 1, 3, 24, 31, 60, 64, 65 _stejnegeri_ (_Mesoplodon_), 24, 77 W Wellander, Capt. Otto, 25 West coast of United States, Ziphiidæ from, 2 Y Yaquina Bay, Oregon, _Mesoplodon stejnegeri_ from, 24