specimen, I feel convinced that that specimen does not belong to M. bidens and that there is a strong probability that it belongs to M. densirostris. It is true that the latter species has been found hitherto only in the Indian Ocean and about Australia, but we know so little about the distribution of the ziphioid whales that, in my opinion, that circumstance by itself should not be given very great weight.

MESOPLODON EUROPÆUS (Gervais).

Dioplodon europæus Gervais, Zool. et Pal. franç., 1st ed., vol. 2, 1848-1852, p. 4; 2d ed., 1859, p. 289, pl. 40, figs. 3-6.

Dioplodon gervaisi Deslongchamps, Bull. Soc. Linn. Normandie, vol. 10, 1866, p. 177.

Neoziphius europæus Gray, Suppl. Cat. Seals and Whales Brit. Mus., 1871, p. 101.

This species was based on a single specimen found floating in the English Channel about seventy years ago. An account of the circumstances under which it was found was given by Eugène Deslongchamps in 1866, as follows:

The head, which forms the subject of this last note, was given to my father some twenty-five or thirty years ago by Mr. Abel Vautier, a merchant and armorer of our town, who died at Paris two years since.

The captain of one of Mr. Vautier’s ships, on his return from a voyage to the colonies, saw floating on the water, at the entrance to the English Channel, the body of a large animal entirely covered by birds (large and small gulls, etc.), which were devouring it. The ship approached the stray, and the captain, knowing that Mr. Abel Vautier was greatly interested in natural objects, had the head of the cetacean cut off, fastened it securely with a cord, and let it trail behind the ship. When he arrived at Caën he made a present of it to Mr. Vautier. The piece had at that time an appearance anything but agreeable. Mr. Vautier was especially fond of beautiful objects which please the eye, and hence he offered it to my father, saying, “You, who are an anatomist, can make better use of this than I can.” My father was unwilling to refuse the present, but neither he nor Mr. Vautier knew as yet of its extreme rarity. It is in fact, up to the present time, the only specimen which exists, and is a unique object in collections.[20]

No additional specimens have been recorded from European waters or elsewhere, and much doubt has been thrown on the validity of the species, many zoologists regarding it as an adult of the commoner species M. bidens. Van Beneden remarked in 1888:

The opinions of naturalists are divided as regards the identity of this ziphioid, which is unique up to the present time. In the eyes of some it represents an old male of the common Mesoplodon, in which the tooth, instead of developing near the middle of the jaw, has developed near the anterior extremity. This is the opinion of Doctor Fischer and others, who think that this unique specimen represents merely an individual modification and that consequently it should not figure in the list of species. We do not share this opinion. It is not impossible that this ziphioid may belong to the other hemisphere, and this would explain why only one single individual has been captured in Europe.[21]

In view of the circumstances surrounding the discovery of the original specimen, it is of great interest to find that two of the specimens from the east coast of the United States represent the same species. As one of them is adult and the other young, the view that the type of M. europæus is merely an old individual of M. bidens is satisfactorily disposed of, as is also the opinion that it represents a singular individual variation.

The two American specimens which represent europæus are those from North Long Branch, New Jersey (adult female; skull, lacking rostrum and mandible, in the Museum of Comparative Zoology), and from Atlantic City, New Jersey (young male; skeleton, cast and photographs in the U. S. National Museum, Cat. No. 23346).

SPECIFIC CHARACTERS.

The species europæus differs from bidens in the following characters, which may be regarded as diagnostic:

Size larger and pectoral limbs relatively shorter and narrower.

The expanded portion of the maxillæ and frontals broader in front of the orbit. The protuberance which projects into the anteorbital notch much larger and the ridge on the maxilla which extends backward from it much higher. Distance from inner margin of maxillary foramen to tip of protuberance much more than one-half the distance between the maxillary foramina of the two sides. Rostrum deeper at the base. Inferior surface of pterygoids more or less convex, with a ridge (in adults) running diagonally across it.

The cranial characters above enumerated are found in the type-skull, as will be seen by examining the excellent figures in Van Beneden and Gervais’ Osteography, plate 24.

In Dr. Glover M. Allen’s account of the Long Branch specimen[22] it is stated that the fishermen who measured it reported that it was 22 feet long, while none of the European specimens (some of which were certainly adults) was more than 16½ feet long. That the measurement reported by the fishermen is at least approximately correct appears from the fact that the skull is larger than that of any of the European specimens. The beak is missing, so that the total length of the skull can not be given, but the distance from the occipital condyles to the line of the maxillary notches (straight) is 312 mm., while in the largest adult among the European specimens this distance is only 260 mm., and in the thoroughly adult Nantucket specimen 282 mm.

SKULL.

The Atlantic City and Long Branch skulls also agree in numerous other details of structure in addition to the foregoing, the more important of which will now be mentioned. Unless otherwise stated, the type-skull, as shown by Van Beneden and Gervais’ figures,[23] also presents the same peculiarities in contrast with M. bidens.

Dorsal aspect (Pl. 2, figs. 1 and 2).—The premaxillæ are more depressed immediately in front of the blowhole than in M. bidens, which, with the prominence of the maxillary ridges, makes this whole region appear strongly concave. The blowhole is narrower absolutely and also relatively to the breadth of the expanded proximal ends of the premaxillæ, so that while in bidens the breadth of the blowhole is much more than one-third the breadth across the proximal ends of the premaxillæ, in europæus it is considerably less than a third. Both premaxillæ are much constricted on the sides of the blowhole and the effect is heightened by the greater expansion of the proximal ends of the former. These ends do not fit closely against the adjoining edge of the maxillæ as in bidens, but leave a transverse vacuity, or trough, which is especially noticeable in the type-skull. The anterior end of the malar