10 MAMMALIA. 



vertebrae are generally broad and shallow, very long in some Rumi- 

 nantia, as the Giraffe, very short, thin, lamellated, and partly anchy- 

 losed together by their bodies and arches, in the Cetacea, as the 

 Dolphin and Whale. A fusion and partial anchylosis occur also in 

 some Edentata, e. g, the Armadilloes, Dasypus, and Chlamyphorus. 

 The atlas is often very large, and the second cervical vertebra has 

 very generally a processns dentatus. The average number of the 

 dorsal vertebrae is, as in Man, 12. Most Apes have from 12 to 14-; 

 the Cheiroptera most frequently 11 ; the Carnivora usually 13; the 

 Ruminantia, Edentata, and Pachydermata 15 to 20 ; the Cetacea, 



11 to 18; the greatest number, 23, occurs in the two-toed Sloth. 

 The spinous processes are for the most part straight and frequently 

 very long, as in the Solipedia, Ruminantia, Pachydermata, for the 

 attachment of the ligamentum nuchae, and form what is called the 

 withers. In the higher Apes they stand obliquely, as in Msn, and 

 cover each other like tiles. They are seldom wanting as, ri Chei- 

 roptera and some Insectivora. The lumbar vertebrae are generally 

 the largest, and in a few instances have inferior spinous processes, 

 e. g. the Hare. Their number is from 3 to 7 ; seldom more. The 

 Anthropoid Apes have mostly 4, the rest of the Mammalia usually 

 more than 5 ; the smallest number is 2 (Myrmecophaga didacty- 

 la), the highest 9 (Loris). In the Solidungula, more rarely in 

 the Pachydermata and fUiminantia, the transverse processes of 

 the most inferior lumbar vertebre are united by ligaments or blended 

 together, a condition which sometimes occurs abnormally in Man. 

 The sacrum, as a rule, is very narro-w, straight, and composed 

 of from 2 to 5 vertebras united together ; t.he Monotremata. the 

 Loris, and most of the Marsupiata, have only a, the Mole has 6. 

 It consists in the Orangs of 4 united vertebras (HI most o\her 

 Apes of 3), and is in them broad like the human sacmm, and 

 slightly concave. In the Ornithorynchus, the sacral vertebrae, re- 

 main permanently separated. The sacrum is exceedingly broad 

 and anchylosed inferiorly to the pelvis in Dasypus. Caudal verte- 

 brae are very generally present, but, as in Man, they are reduced 

 in some of the higher Apes to 4 or 5 aborted vertebros. They are 

 usually very numerous 20 or 30, and in some Edentata even 40, 

 and beyond that number. The first caudal vertebras are very simi- 

 lar in form to true vertebrae ; they have the usual processes, and 

 very generally inferior spinous processes also. Toward the end 

 of the tail they always dwindle gradually in size, lose their pro- 

 cesses, and become simple ossicles, resembling the phalanges of the 



