Notes on the Preparations mentioned in the foregoing Paper.
The three Whales described by Dr. Knox in the foregoing paper, are evidently to be classed with the Family Ziphidœ, as defined in Dr. Gray's Catalogue of Seals and Whales, p. 326.
Plate XIV. gives three views of the skull (two feet in length) of the young specimen that was captured in Porirua Harbour, in 1866, the dimensions of which have already been given (Trans., Vol. ii., p. 27.).
Figure 1 is the side view without the lower jaw, Figure 2 shows the upper surface, and Figure 3 the lower surface of the same. The curious obliquity of the skull, which twists forwards and upwards to right half of it, as shown in the drawing, especially by the relative position of the two segments of the blow-hole, is matter of remark, as it is found to exist in all the specimens of whales and their allies yet examined, and probably corelates with some modification of the progress of the animal through the water, to enable it to enjoy direct forward vision.
Plate XV. gives three views of the lower jaw belonging to the same head. In Figures 1 and 3, which are the profile and inferior views, it will be observed
that there are three nutrient canals at the tip of the jaw on each side, probably indicating the normal number of teeth. In Figure 2, which shows the upper surface of the jaw, there is only one socket on each side (a and á), which held the tooth figured of natural size (4a and 4b.) The upper conical part of this tooth has a polished surface, but never protrudes through the gum.
This is well shown in Figures 5a and 5b, the first of which shows the left side of the top of the jaw, with the integuments still in place, the position of the tooth being only revealed by a slight elevation without any aperture. The second shows the opposite side of the jaw with the integuments removed, and the tooth which came away imbedded in a fold of the gum, dissected out and replaced in the socket.
Plate XVI. gives the superior, inferior, and profile views of the skull of the third specimen referred to by Dr. Knox; the dimensions of which are as follow:—
|Length of head||59.5|
|" dental groove||15.0|
|" lower jaw||43.0|
|Width of notch||14.5|
|" at orbits||24.5|
|Height of occiput||19.5|
Plate XVII. gives the corresponding view of the lower jaw (Figures 1 and 2), and also the tooth (Figures 3a and 3b), both in side view and in section, showing the internal structure. The form of the tooth is more turned than in the other specimen, but the variety is probably due to age.
The preparation of the nose (Figures 4a and 4b), show that notwithstanding this is a full-sized animal, the tooth is still sheathed in the gum, being imbedded in a tough cartilaginous sac, which adheres loosely in the socket of the jaw, and is moved by a series of muscular bundles that elevate and depress it.