I. Fossil Cetacea.[732]—The Cetaceans, although popularly termed fishes, are as perfect air-breathing vertebrated animals, as the terrestrial mammalia, and, like them, give suck to their young. Instead of fore-feet or arms, they have a pair of fins or paddles, but are destitute of hinder extremities, the place of the latter organs being supplied by a powerful cartilaginous horizontal fin, appended to the tail. The Cetaceans, therefore, differ in this respect from the fossil marine reptiles, the Ichthyosaurus and Plesiosaurus (see p. 662), which have two pairs of paddles. This order, as is well known, comprises the most colossal forms of animal existence,—the Whales. Some are herbivorous, others carnivorous; many have powerful teeth; others are edentulous, the jaw being furnished with a series of elongate plates of the substance familiarly known by the name of whale-bone.
[732] Cetacea: an order of aquatic mammalia, comprising the W hales, Narwhals, Porpoises, Dolphins, and Dugongs.
The fossil remains of Cetaceans have, for the most part, been observed in alluvial silt and beds of drift, in valleys still traversed by rivers; but many examples have been discovered in elevated sea-beaches, proving that, although, geologically speaking, these beds are of modern origin, yet great changes in the relative level of the land and sea must have taken place since these remains were imbedded. Thus, on the banks of the river Forth, near Alloa, in Scotland, the skeleton of a Whale (Balænoptera), seventy-two feet long, was discovered imbedded in clay, twenty feet above the highest tide.[733] Cuvier mentions the discovery of bones of a Lamantin at Angers; of a Dolphin, and Rorqual, in Lombardy; and of a Grampus, in the pliocene of the Sub-Apennines.[734]
[733] Dr. Fleming’s British Animals, p. 39.
[734] For notices and descriptions of Cetacean remains found in England, see Owen’s Brit. Foss. Mammalia, p. 516, et seq.
Otolithes of Cetaceans.—Petro-tympanic bones of several large whales have been found in great numbers in the red Crag of Felixstow; among them is one of the genus Physeter, or Sperm-Whale.[735]
[735] Proc. Geol. Soc. for 1845, p. 41; and Brit. Foss. Mam. p. 526, &c.
Brighton Fossil Whale.—An interesting discovery of the anterior half of one side of the lower jaw of a Whale, undoubtedly coeval with the extinct Mammoth (Elephas primigenius), was made in 1828 in the Cliff, east of Kemp Town, Brighton, under the following circumstances. On the face of the Cliff, in the ancient shingle which lies immediately upon the chalk and is surmounted by beds of calcareous rubble, containing bones and teeth of Elephants, to the height of one hundred and twenty feet, some fishermen had observed a huge bone, that had been laid bare by an unusually high tide and now projected two or three feet beyond the face of the Cliff. Unable to remove it, they broke off the extremity, a fragment of which was sent to me. Upon repairing to the spot a few days afterwards, I found that the fishermen had renewed their attack, and demolished a considerable portion of the bone in ineffectual attempts to dislodge it from its bed; and had desisted only from the apprehension of being buried beneath the overhanging cliff, which is composed of loosely aggregated materials. Unfortunately, the bone extended directly into the cliff, and it required several hours of labour, not unattended with danger, before an excavation was made sufficiently large to expose the entire specimen. It proved to be the anterior nine feet of the left branch of the lower jaw of a whale-bone Whale (Balæna mysticetus). It was of a light fawn colour externally, but the internal coarse osseous structure was delicately white; it was extremely brittle, and, upon attempting to move it, broke into a thousand pieces. Time would not permit of the application of a coating of plaster of Paris, for ere we had completed our task the tide was rapidly approaching, or this interesting relic might have been extracted entire. This portion of lower jaw, before it was mutilated by the fishermen, was twelve feet long, and thirty-six inches in circumference at the largest extremity. It must have belonged to a Whale from sixty to seventy feet in length.[736]
[736] The fragments of this jaw that were preserved are now exhibited in the British Museum, in Room V.
In the fluviatile silt of the valley of the Ouse, near Lewes (Wond. p. 63), the skull of a Porpoise and a portion of the cranium, with the socket of the long straight tooth, of a Narwhal (Monodon monoceros), were found twelve feet beneath the surface of the soil.