In regard to differences between this skull and those of _M. densirostris_ it should be stated that in the latter the premaxillary foramina are situated farther apart, and that the maxillary foramina are situated considerably in advance of those of the premaxillæ instead of nearly in line with them. The Annisquam skull approaches _M. europæus_ in several characters, but these are such as _europæus_ shares with _densirostris_. The principal ones are the breadth of the maxillæ in front of the orbits, the presence of the malar in the base of the anteorbital notch, and the convexity of a part of the inferior surface of the pterygoids. Dr. Glover M. Allen has given an account of the exterior, skeleton, and teeth of this specimen, from which the following particulars are extracted:[19] Regarding the Annisquam specimen no color notes were taken, but from a few small photographs in the possession of the Boston Society of Natural History, it appears evident that the ventral portion was of a lighter tint, and in one of the views a few oval whitish spots are seen on the side a trifle behind the middle portion of the body. Another view shows the convexity of the posterior margin of the flukes at the median point, as well as the prominent dorsal fin. The lower jaw protruded slightly beyond the upper. Measurements of this specimen, as noted by Professor Hyatt, are as follows: Total length, 12 feet 2 inches; from anus to bight of flukes, 3 feet 4 to 6 inches; across flukes, 3 feet 1 inch; from tip of rostrum to angle of mouth, 1 foot 1½ inches. The gular furrows were noted as about 10 inches long and from ¼ to ½ an inch deep. The teeth of the Annisquam specimen barely projected above the alveoli of the jaws and are sharply mucronate. The basal portion of each, however, is more like that of the male’s tooth [_M. europæus_] in the slightly convex posterior outline and the forward extension of the anterior angle. * * * The Annisquam skeleton has 45 vertebræ. Four of the seven cervicals are fused. The atlas, axis, and third cervical are firmly anchylosed throughout, save for the lateral foramina for the passage of the cervical nerves. The fourth cervical is fused to the third by the dorsal spine on the left side and by the tip of the upper lateral process of the same side. Its centrum, right half of the dorsal spine (the spine is divided medially), and the remaining lateral processes are free. * * * The epiphyses of the fourth and fifth cervical vertebræ and the anterior epiphysis of the sixth cervical are fused to their respective centra, but all the other epiphyses of the vertebral column and of the pectoral limbs are free.