TAPIEINA. 253 



The skulls of the American Tapir and of S. Baird's Elcismognathus 

 in the British Museum show this peculiarity. 



The skull of a young American Tapir in the Museum Collection 

 shows the same pecuUarity. In this specimen, which has lost all its 

 milk-teeth, the development of the alveoles is not so uniform, the 

 cavities left by the milk-teeth being much larger and more or less 

 broken away on the outer edge ; while the inner series of pits, from 

 which the permanent teeth are to be developed, are much smaller, 

 shallower, and far apart ; perhaps they would have been larger and 

 more developed if the animal had been allowed to live ujitil the per- 

 manent teeth were more developed. 



The space between the two series is much larger in the skull of 

 the ElasmognatJiHS Bairdi. The skull of the younger specimen of 

 E. Bairdi in the British Museum has lost aU its milk cutting-teeth 

 in each of the jaws, each leaving a well-marked, regular, circular, 

 conical cavity on the edge of the jaw. Just within these cavities, 

 but well separated from them by a bony plate, and alternating with 

 the cavities of the milk-teeth, is placed a regular series of six well- 

 developed similar, but not quite so large, circular, conical cavities. 

 At the base of each cavity is to be observed the commencement of a 

 tooth, being the teeth of the permanent series. But the cutting- 

 teeth of the lower jaw are more unequal in size, the central cavities 

 being the largest, and gradually diminishing in size to the outer one. 

 In the skulls of the young American Tapir and of the E. Bairdi 

 there is a second cavity on the inner side of the base of the milk- 

 canine. In the skull of T. araericanus one of the milk-canines is 

 remaining; it is of very small size, and compressed lancet-shajied 

 in form. In the skull of E. Bairdi the milk-canines are shed. 



In the skull of the young Tajiirus americanus in the British Mu- 

 seum, which has shed its cutting-teeth, there is an abnormal tooth 

 (probably a false grinder) to be observed on each side of the maxilla, 

 rather in front of the middle of the space between the base of the 

 canine and the front edge of the first grinder. They are each placed 

 on the outer side of the jawbone, near the lower edge, and are co- 

 vered with well-developed enamel, and are similar in form and size. 

 Are these teeth similar to the front or false grinders in Anoplo- 

 therium ? 



llie family may be divided into two groups or tribes. 



Tribe I. TAPIRTN^. 



The nasal aperture elongate, gradually contracted into a narrow 

 opening in front, extending nearly to the root of the upper canines. 

 The upper jaws only united in front as far as the root of the canines ; 

 the upper part of the sides of the nasal aperture broad, rounded. 

 The internasal cartilage only ossified at the hinder part under the 

 nasal bone. 



il. Cuvier. in the ' Osscmens Fossiles," vol. ii. p. 14."). gives the 



