The order Cete is thus summarily defined by its great founder : Spiracles upon the head. Pectoral fins and horizontal caudal fin without claws.
Genera :—Ilkmodon, Balcena, Physeter, Ddphines.
This, the last order of the Linniean Mammatia, is immediately preceded by the Pettus:v.
For Lacdpede's arrangement, see his Histoire Naturelle, &c. Des C6tac6s„' 4to., Paris, 1804.
The Made form Cuvier's ninth and last order of Mammiferes, the Ruminants Linn.) being the eighth.
Cuvier defines the detaccans to be mammiferous animals without posterior feet. Their trunk, he states, continues itself with a thick tail, which a cartilaginous horizontal fin terminates; and their head is joined to the trunk by a neck so short and thick that no narrowing or constriction of the part is perceptible, and composed of cervical vertebrre, which are very delicate, and in part conjoined or soldered together. Their anterior extremities have the first bones shortened, and the succeeding hones flattened and enveloped in a tendinous membrane, which reduces them to true fins. This gives nearly entirely the external form of the fishes, except that these last have the tail-fin verticaL The Cetaceans therefore remain constantly in the water ; but as they respire by means of lungs, they are obliged to come frequently to the surface for air. Their warm blood—their ears open externally, although with very small apertures—their vivi parous generation, the teats by means of which they suckle their young, and all the details of their anatomy, sufficiently distinguish them, Cuvier observes, from the fishes.
The same great zoologist remarks that their brain is large, and its hemispheres well developed ; the petroua bone, or that portion of the cranium which contains the internal ear, is separated from the rest of the heed, and only adheres thereto by ligaments. There is no external ear, nor are there any hairs upon their bodies. The form of their tail obliges them to move it from above downwards for their pro- I grossive motion, and aids them greatly in raising themselves in the I water.
To the genera which up to Curler's time naturalists had reckoned among the Cdaeea, he adds those which had formerly been con founded with the Waimea', and which form his first family, namely,— The Herbivorous Cetaceans.
The teeth of these have a flat crown, which, Curler remarks, determines their mode of life, leading them often to leave the water to creep and feed on the bank : these have two teats on the breast, and hairy moustaches; two circumstances, ho observes, which when they have been seen from a distance, with their heads raised vertically out of the water, have given them some resemblance to women or men, and have probably given origin to the stories of some travellers who pretend that they have seen Tritons and Syrens. Although iu
the cranium the bony nostrils open upwards, they are only pierced in the skin at the end of the muzzle. Their stomach is divided into four pouches, two of which are lateral; and they have a great mecum. Cuvier divides the Herbivorous Cctacea into 1st, The Lamantine, or rather Manatees ('Manatees, Cur.); 2nd, the Dugongs, Lacdp. (Balicore, Ill.); 3rd, the Stelleres, Coy. (Rmana, Cuvicr's second family of this order consists of— The Ordinary Cetaceans.
These are distinguished from the preceding by the singular appa ratus which has procured for them the French name of Souffleurs, or Blowers. As they take, Ogether with their prey, says Curler, large volumes of water into their very spacious mouth, there was a necessity for some outlet to get rid of it ; it passes across the nostrils by means of a particular disposition of the velum palati, and is collected in a sac placed at the external orifice of the cavity of the nose, whence it is driven out with violence by the compression of powerful muscles by a narrow aperture pierced at the top of the bead. Thus it is, adds Cuvicr, that they produce those jets d'eau which cause them to be seen from afar by voyagers.
He further observes that their nostrils, incessantly traversed by floods of salt water, could not be lined with a membrane sufficiently delicate for the perception of odours. The whales therefore aro without those projecting lamina" which are to be found in other animals ; the olfactory nerve is wanting in many, and if any of them enjoy the sense of smelling they must have it very much obliterated. Their larynx, of pyramidal form, penetrates into the back nostrils for the reception of the air, and for the purpose of conducting it to the lungs, without any necessity on the part of the animal to lift its head and mouth out of the water : there are no projecting laminae in their glottis, and their voice must be reduced to simple bellowing.. They have no vestige of hair, but their body is covered with a smooth skin, tinder which lies the thick blubber abounding in oil, and the principal object for which they are sought. Their teats are near the anus, and they are unable to seize anything with their fins. Their stomach has five, and sometimes as many as seven, distinct pouches. In lieu of a single spleen they have many small and globular ones ; those which have teeth have them conical, and similar to each other. They do not masticate their food, but swallow it rapidly. Two small bones, suspended in the flesh near the anus, aro the only vestiges of posterior extremities. Many have on the back a vertical fin of a tendinous substance, but not sustained by bone. Their flattened eyes have a thick and solid sclerotic ; their tongue has only smooth and soft integuments.