Xil. 
with the occipital region of the cranium ; these vertebre con 
stitute the framework of the neck, and in all known recent 
Mammals, except three—the Manatee (Manatus australis), the 
Two-toed Sloth ( Cholepus hoffmanni) with six, and the Three-toed 
Sloth (Bradypus tridactylus/ with nine—consists of seven distinct 
bones, which, however, are in the case of several genera, notably 
belonging to the Cetacea, in a greater or less number ankylosed 
together so as to form a solid mass. The second cervical vertebra 
is termed the amis, and, except in certain CETACEANS, always de- 
velops a well defined odontoid process. 
Dorsal, or Thoracic.—Behind these lie the dorsal, or, since to 
its vertebre only are articulated the movable ribs which form 
the arch of the thorax, as it would be more correct to term it, 
thoracic region; the anterior rib is attached below to the sternum 
(vide infra), as are also usually several of those which follow. 
Lumbar.—The lumbar region consists of those vertebree in 
front of the sacrum which bear xo movable ribs. The number of 
vertebrz in the conjoined thoracic and lumbar regions is tolerably 
constant in any given group of animals, any increase of the one 
being at the expense of the other; the smallest number of 
thoracico-lumbar vertebre occurs in the Armadillos (/ Dasypodide ) 
which have only fourteen, while the greatest number is found in 
the Hyrax or Rock-Rabbit, the supposed Cony of the Scriptures, 
in which no less than thirty are present; in Man, the higher 
Apes, and most Bats, the number is seventeen; in nearly all 
Marsupials, nineteen. 
Sacral.—The sacral region is that which is situated between 
the lumbar and caudal regions; in it the vertebre are ankylosed 
together so as to form a single mass ; the number of vertebre 
included in the sacrum is variable, even in different individuals 
belonging to the same species, especially as age advances, when 
certain of the caudal vertebree become incorporated with those of 
the true sacrum. ‘These bones are absent in the CETACEA. 
Caudal.—The caudal vertebree are those placed behind the 
sacrum, and terminate the vertebral column. They naturally vary 
greatly in number, there being usually four only in Man, and those 
rudimentary, whereas in the West African Long-tailed Pangolin 
(Manis longicaudata) there are as many as forty-six. They are 
also, for obvious reasons, numerous and highly developed in the 
Macropodide and the CETACEA. 
Chevron Bones.—To the under-surface of the caudal vertebre 
of many Mammals, in which the tail is well developed, are 
attached by articulation small bones, of the shape of an inverted 
arch, which have received the name of “ chevron bones.” 
Sternum.—The mammalian breast-bone (sternum) is a bone, or 
series of bones, placed longitudinally in the mesial line, on the 
inferior aspect of the thorax, and connected with the vertebral 
column by a series of more or less ossified ribs. It is divided 
