The single bone of the sternum was oblong, widest in front, and carried on each side an articular facet for a rib.
The ahoulder-bhule is nearly flat; one can scarcely perceive a alight concave curvature : it is nearly fan-ehaped, and less wide then high. Its anterior border is simple, end has only a single projecting apo phymia, which from its position is probably the neromion. Its articular head is much wider in proportion than in the Caellislot. The humerus is stout and short, scarcely twice as long as it is thick. Its tuberosity does not reach beyond the head in front ; this last is hemispherical, and nearly parallel to the axis. The lower head is divided into two slightly inclined planes for the ulna and radius, which two bones are compressed; the ulna is the narrowest, especially in its middle. its upper head is slightly oblique at its axis, and the olecranon ascends a little instead of recurring into a book, as in the Cachalot. The radius enlarges below, so as to be there two-thirds of its length ; above it is not more than a third. There are four carpal bones us the first row, of which the liloar bone, which responds to the pieiform, forme a pro Digestive Orgaus.—Phytophagous Cataceaue.—The teeth (molars) of the Manatees are ridged doubly or trebly, the root distinct from the crown here the resemblance to the pachyderms, Tapir and Ilippopo tames for instance, is very strong. The molars of the Dugongs arc elliptical, without true fangs, and with two alight furrows on the unworn crown, which disappear with age. In the upper jaw are twc tusks. In the Rytimethere are no molars; but there is in lieu of there a horny plate in the middle of each jaw. The tongue is short, and car hardly be endowed with much motion. The form of the oa hyoides if simple: anehylosis between the body and posterior cornua soot supervenes ; but the latter send no ligament to the thyroid cartilage The anterior cornua remain generally cartilaginous, and are the modiurr of union between the body, or basi-hyal, and the large and long stylok processes.
Professor Owen states that the opening of the larynx is chief!) defended, during the submarine mastication of the vegetable food of the Dugong, by the extreme contraction of the faucial aperture, which resembles that of the Capybara. No pyramidal larynx traverses it as in the true Cd (teem Two large parotid glands aro situated immc diately behind the large ascending rams of the lower jaw. A Udell layer of simple follicular glands is developed above the membrane o the palate, and a glandular stratum is situated between the meow and muscular coats of the lower part of the meophagua Professor Owen states that n similar but more developed glandular structure ir present iu the (esophagus of the Hey. He then observes that the stomach of the Dugong presents, as Sir Everard Home had justly observed, some of the peculiarities met with in the Whale Tribe, the Peccari and Hippopotamus, and the Beaver : like that of the first is divided into distinct compartments ; like the second and third has pouches auperadded to and communicating with it ; and like the last it is provided with a remarkable glandular apparatus near the cardia. These modifications, the Professor remarks, obviously liar
monism with the difficult digestibility and low-organised matter of the food of the Dugong. " Yet," says be, "it is n fact that would no have been h priori expected, that in the Carnivorous Cdacea th stomach is even more complicated than in the Herbivorous species and presents a closer resemblance to the ruminant stomach ; it i divided, for example, into a greater number of receptacles, rind Im the first cavity like the rumen lined with cuticle ; while in thi Dugong, on the contrary, the stomach is properly divided into tw parts only (of which the second touch more resembles intestine), am both are lined with n unicorns membrane." After a luminous detailes account of the stomach, Professor Owen observes that it would men that a cascum —and he minutely describes that of the Dugong—i present in all the Herbivorous Cetatea : for Steller notices it as o large size and sacculated in the Northern Manatee (Stellerua); ens Daubenton has given n figure of the bifid mourn in the Southen Manatee (Manatus Americartas). it is interesting, he adds, to fire that a caput cob (the situation and structure of which in the Dugom he describes) is present in the true Creacea, as the Bahrnida., wideh subsist on animal food of the lowest organised kind. The whole o the alimentary canal and the individual differences presented by th three specimens having been elaborately detailed, Professor Owe proceeds to point out that the Dugong with respect to the biller organs deviates in a marked degree from the ordinary Cetacea, in the presence of a well-developed gall-bladder, an organ which Daubenton also found in the Manatee. But the presence of the gall-bladder is not, the Professor observes, constant in the Herbivorous Cetacea ; for in the Northern Manatee, according to Steller, it is wanting, and its absence seems to be compensated by the enormous width of the ductus corn numis choledochus, which would admit the five fingers united. The secretion of the pancreas was carried by from twenty to thirty ducts, each about two lines in diameter, to a very wide common excretory canal, which terminates below, but on the same prominence with the cystic duct, at a much greater relative distance from the pylorus than in the true Cetacea. In one of the Dugongs dissected by Professor Owen were two small accessory spleens in addition to the larger rounded one, but in the other specimens the last alone was present. (' Zool. Proc.,' 1833.) Zoophagous Cetaceans.—The teeth of the Dolphins are generally simple and conical or compressed. They are present in both jaws ; their number varies, and they not unfrequently lie hid in the gums a rudimentary state. Those of the Cachalots are simple, of a long ovoid recurred shape, and placed in the lower jaw only. The Mysti cetes, or Whalebone Whales, are without true teeth ; in lieu of which, transverse horny plates of baleen, or whalebone, as it is commonly termed, grow from the palate. These plates on their internal edges are fringed with loose beards, and among these the small marine animals which form their food are entangled as in the meshes of a net.