The furrows converged posteriorly; they were separated by an interval of ⅝ inches anteriorly and 5⅛ inches posteriorly. Between the anterior ends of the main furrows was a small one, about an inch long, but it is doubtful whether this was a natural fissure. I did not observe it when the whale was in Atlantic City. The natural color of the specimen had largely disappeared before I examined it, but Captain Gaskell and others who saw it while still fresh agreed that it was very dark slate-gray on the back, lighter on the sides, and whitish on the belly. I observed that a broad area between the pectoral fins was slate-gray, and contrasted with the white of the throat and belly. The whitish color ended somewhat abruptly and irregularly at the anus, and the flukes, as well as the pectoral and dorsal fins, were probably very dark slate-gray, or blackish, when fresh. The epidermis was exceedingly smooth and glossy throughout. The tongue was purplish-white. The roof of the mouth was black, except at the posterior end, where there was an irregular area of pinkish-white. The integument of the roof of the mouth was smooth and shining. Its surface was convex at the extremity of the beak, but the central portion was concave, while at the posterior end it was again raised into a rounded pad. In these respects the shape of the integuments coincided with that of the underlying maxillæ, upon which they were closely fitted. The sides were rounded, and a shallow groove intervened between them and the lips. This groove was continued around the roof of the mouth behind, and formed a demarcation between this part and the œsophagus. The tip of the tongue was 7½ inches from the extremity of the jaw. It was oval in outline, the extremity is obtuse, and it was entirely bound down. The margin was entire, and not crenulate, as in many dolphins. Dorsal and ventral views of the stomach are shown in Pl. 40, figs. 1 and 2; a dorsal view of the lungs in Pl. 13, fig. 5; and of the perineum in Pl. 40, fig. 3. A description of the gross anatomy is reserved for a subsequent paper. The external dimensions of the Atlantic City specimen of _M. europæus_ are given in the following table, together with those of nine European specimens of _M. bidens_ taken from various authors, and assembled here for purposes of comparison. The dimensions of the Annisquam specimen which, as already explained (p. 9), represents a third species, are also added. _External dimensions of Mesoplodon europæus, M. bidens, and M. densirostris._