Plate 4 SKULLS OF MESOPLODON
Fig. 1. Mesoplodon bidens. Skull. Nantucket, Mass. Female, adult. Mus. Comp. Zoöl. No. 1727. Ventral aspect. About ¼ nat. size. Tip of beak, left pterygoid, and malars defective.
2. Mesoplodon densirostris? Skull. Annisquam, Mass. Female, young. Boston Society of Natural History. Ventral aspect. ¼ nat. size.
Left frontal region defective.