include any intervertebral cartillages, which would add appreciably to the total length of the spinal column.

As far as I have been able to determine by study of skeletons of recent specimens, the total length of the Halifax specimen when living must have been not far from twelve feet, and this corresponds very well with the size of living Monodons, to which genus, as will be shown later, this specimen is referred. Specimens of living Monodon monoceros that have been taken are from ten to fourteen feet long, so that the Halifax specimen is of about average size.

The variation in form of the centrum in different vertebræ is well seen by comparing different figures of Plates xviii and xix, which give the width as compared with the height in the dorsals and the almost circular form found in lumbar, and the still more entirely circular outline of the centrum in the caudals.

Still, the centrum is wider than high in all vertebræ before the eighth. After this the height grows a little greater than the width. The length of each centrum or body increases from the first to the thirteenth. From here it decreases to the end.

The neural canal is largest in the first. Here it is broadly oval, much wider than high. In the third, which, as before stated, is probably the eighth dorsal and the only other vertebra in which both width and height can be measured, the width is reduced to 57 mm. and the height from 73 mm. to 38 mm., and, as the figures in the table of measurements show, it goes on diminishing until in the last of this series, which is probably about the fourteenth caudal, it is only 4 mm. wide.

THE STERNUM.-As Plate xx shows, this bone is thick and large. It elements are completely united so that no trace of suture can be found.

Although the bone is considerably broken, yet enough remains to show pretty nearly its original form. This is less distinctly triangular than in many of the cetacea. As the plate shows, the upper part of the left side and the lower part of the right are nearly whole. Articular surfaces for three ribs are plainly shown, but those of the other three, there being normally six ribs connected with the sternum in Monodon, are wanting.

Exact measurements cannot in all cases be given because of the broken condition of the bone, but the following are nearly correct: Length, 9 inches (229 mm.); width across the upper end, 71⁄2 inches (191 mm.); width across the lower end at the articulations,

34 inches (83 mm.). The thickness at the top is 11⁄2 inches (38 mm.). The general thickness is on the average rather more than 3/4 inch.

Longitudinally the bone is only slightly curved and the surfaces are, as a whole, nearly flat.

Plate xx shows the sternum, four ninths natural size.

THE SCAPULA.-Parts of both scapulas are among the bones saved. They are thin, fragile and badly broken. Hence their original form cannot be definitely ascertained. They appear to be unusually thin and small for an animal of such size. A considerable part of the glenoid cavity is intact and this part of the bone is heavier and more solid than the rest. Each is about 24 inches (57 mm.) in diameter vertically.

SPECIFIC POSITION OF THE HALIFAX WHALE.

In Doctor Gilpin's description of this specimen we find the following: "The fragment of the lower jaw so exactly resembles the cut in Dana's Geology of Beluga vermontana as to hazard the conjecture that they are closely allied if not identical." Students of this group do not need to be told that this is a wholly valueless identification. And yet, since Doctor Gilpin's account, his suggestion that his specimen was of the same species as Thompson's Vermont specimen has been allowed to pass without a word of dissent, so far as I can find. After the Halifax bones had been sent by the kindness of Mr. Piers, curator of the museum, they were taken to Montpelier and compared with those there. It needed only the briefest examination to show important points of difference, and had the Canadian specimen been as complete as the Vermont, it is probable that the differences would have appeared even greater.

Very fortunately in both specimens the periotic, which for specific identification is most important, was present. An examination of Plates xvi and xx will indicate how dissimilar are these bones. So also there are differences in other bones. It is not necessary to go into an extended comparison of the two skeletons here. It must be sufficient to call attention to a few of the most evident and important points.

Taking up the periotics as more important than any other of the bones, we may note the remarkable differences to which attention has already been called as they appear in Plates xvi and xx. In this case it is possible to quote the opinions of Doctor True of the U.

S. National Museum, who is, I suppose, the peer of anyone in America as an authority on the cetacea, and Mr. Andrews of the American Museum, who is also a special student of the group and one of the best authorities.

At the time of my consultation with Doctor True, I was unable to show him the actual bone, but after studying a series of photographs of the bone, he wrote as follows:

"As regards the Nova Scotia specimen, I think there is no doubt that it is not Delphinapterus, on account of the shape of the periotic and the short lumbar vertebræ. Our skulls of Monodon, unfortunately, are without the periotics so that I cannot make comparisons of importance, but Van Beneden and Gervais' figures indicate a shape similar to that shown in your photographs. None of the latter, how

ever, are from the same point of view as the figure.”

Mr. Andrews had the bone itself and reported:

"I have just finished a comparison of the periotic bone which you sent with that of Delphinapterus leucas and of Monodon monoceros. As soon as I looked at the periotic of this specimen it seemed to me that it resembled very closely the corresponding bone of Monodon. A comparison shows that in size and general shape it agrees very much better with M. monoceros than with D. leucas, in fact the whole shape of the bone is decidedly unlike Delphinapterus.

"In order to verify my opinion I showed the specimen to Dr. W. D. Matthews and he agreed with me that, while there are some points of difference between the periotic of this specimen and that of Monodon, yet it is certainly closer to that genus than to Delphinapterus.

"Your specimen, on the other hand, agrees well with Delphinapterus, consequently it would seem to me unlikely that it and the Halifax whale can be of the same species or even the same genus. The tympanic and periotic are, so far as I am aware, subject to less individual variation than any other bones in the cetacean skeleton and the remarkable difference shown in the Halifax whale would seem to me good grounds for a pretty close investigation of the species if it has been referred to Delphinapterus. Of course, if you could see the rostrum of the Halifax specimen and determine whether or not the upper teeth were present, it would simplify matters very greatly, for Monodon has no teeth aside from the tusk."

Very much to my regret, I was unable to submit any of the bones

of the Halifax specimen to so eminent an authority on cetacea as Dr. F. W. True. I was able at a later time to compare photographs of this specimen with the very fine skeletons of Monodon in the New York Museum. As a result of all this it seems quite certain not only that the Halifax specimen is not Delphinapterus, but that it is Monodon. It is doubtful whether it can be determined with entire satisfaction whether it is identical with the living M. monoceros or a closely allied extinct species.

Authorities recognize but one living species of Monodon and this has been several times found as far south as England, though its habitat is given as Arctic seas. Nicholson and Lyddeker, Manual of Paleontology, page 1307, says that: "Remains of Narwhal, Monodon monoceros, are in the Norfolk forest beds and the Pleistocene of Alaska." In Transactions of the Zoölogical Society, London, 1866, Professor Flower proposed the group Beluginea to include Delphinapterus and Monodon.

OTHER CANADIAN SPECIMENS.

All the other Canadian specimens that have been found, so far as I know, are enumerated in the list on page 79.

Whether these are to be referred, as they have been, to Thompson's D. vermontana or D. leucas can hardly be quite fully determined. In some cases, the bones that have been found are not such as to make definite specific identification possible. So far as they are concerned the specimen might be either of the above species.