OSSEOUS SYSTEM. 7 



of Man, as the Bushmen-Hottentots. The nasal bones are very 

 long and conspicuous in the Solidungula and Ruminantia, and of re- 

 markable length in the Porcupine. The Cetacea, as the Narwhal, 

 have a pair of very small, rounded, and somewhat asymmetrical nasal 

 bones, situated far back. The lacrymal bone appears to be very 

 rarely wanting, as in the Seal and Walrus, or to become confluent 

 with adjacent bones, as in the Ornithorynchus and Echidna. It ex- 

 ists only as a small imperforate plate in Manatus and Halicore, 

 while in the rest of the Cetacea it is merely an appendage of the 

 frontal bone. In the Solidungula and Ruminantia it is very large, 

 and is frequently, as in the Stags, provided with a deep pit or 

 groove for the reception of the sebaceous sacs. The malar bone is 

 very seldom wanting, as in Manis ; but it is very small, thin, and 

 flattened in the ordinary Cetacea. In Myrmecophaga it presents 

 the form of a small thin scale, which is, as in the Tardigrada and 

 in Centetes, not united by a complete zygomatic arch with the tem- 

 poral bone. In the Sloths it gives off both above and below a free 

 and pointed process of considerable size. In the Carnivora it is 

 very much developed, and forms a very strong arch, convex exter- 

 nally. Its frontal process seldom reaches the bone of that name, 

 and it is only in the Solidungula, Ruminantia, and Makis, that the 

 union takes place between them so as to complete the ring of the 

 orbit externally. It is only in the Apes that an inner plate is devel- 

 oped like that of Man, which circumscribes completely the orbit and 

 zygomatic groove. The palatal bones are small in Man and in the 

 Apes, and most conspicuous in the Carnivora. The vomer is gen- 

 erally present, and is sometimes, especially in the Cetacea and Ru- 

 minantia, a perpendicular plate of considerable size. Numerous 

 differences are exhibited by the superior and intermaxillary bones. 

 The intermaxillary, which, in Man, is found only in the earliest 

 foetal period, occurs in all the Mammalia, and supports the incisive 

 teeth, except when it is devoid of teeth, as in the Ruminantia. 

 It is, therefore, particularly conspicuous in animals provided with 

 large incisors, as in the Rodentia and the Elephant, where it ex- 

 tends far backward, abutting against the nasal bones and vomer, 

 and more rarely still against the frontal or the malar and lacrymal 

 bones. It is very seldom, as in the Ornithorynchus and Unau (two- 

 toed Sloth), divided again upon each side into two portions. In 

 ro&tty^heiroptera the intermaxillaries are separated by a remarka- 

 ble interval m u^ mjddle from each other, as in the malformation 

 called cleft palate mM^, The lower jaw consists in the Apes, 



