VERTEBRATA. 251 



bones, confined (except in the reindeer) to the males, frequently 

 branched and always deciduous, as in the deer family ; neither of 

 these are true horns ; the latter are, indeed, more generally called 

 antlers. The horns in the ox and antelope families are hollow 

 and persistent, consisting of a bony core covered by a corneous 

 Ease. These are known as the Cavicornia. The nasal horns of 

 the Ehinoceroses are composed of concrete hairy fibres, closely 

 compacted and fixed on a bony protuberance. 



In the ruminant families the feet are bisulcate, with two sup- 

 plementary hoofs in some, placed above and at the back of the 

 foot. Camelidas (=Tylopoda, Phalangigrada) have two toes, 

 callous beneath, the hoofs scarcely more than rudimentary. None 

 of the Ungulata have clavicles. 



The stomach is divided into four compartments the two upper 

 essentially dilatations of the oesophagus, the third or, rather, per- 

 haps the fourth, being the true stomach. In the stag family there 

 is a sebaceous gland [lachrymal sinus] in front of the eye, secreting 

 a disagreeable waxy substance. 



The placenta is diffused in the camels and in non-ruminants ; 

 and is cotyledonary in the true ruminants. 



The Ungulata pretty nearly include the old orders Belluse, 

 Pecora, Euminantia, Pacbydermata, and Solipeda or Solidungula. 

 They were divided by Owen into two orders Artiodactyla and 

 the Perissodactyla (the former with paired, the latter with un- 

 paired toes) ; these are now reduced to suborders. 



The animals most important to man are included in the 

 Ungulata. Among them are the camel or dromedary (Camelus 

 dromedarius), the wild camel, now domesticated ( Camelus bactri- 

 anus), alpaca (Auchenia pacos), lama (Auchenia lama), giraffe 

 (Camelopardalis giraffa). stag (Cervus elaphus), wapiti (Cervus 

 canadensis),roeb\ick ( Cervus capreolus), reindeer ( Cervus tarandus), 

 elk (Alces male his), fallow-deer (Lama platyceros), musk-deer 

 (Moschus moschiferus). saiga (Colus tataricus), gazelle (Antilope 

 dorcus), water-buck (Cervicapra elllpsiprymtms), chamois (Rupi- 

 capra tragus), ibex (Capra ibex], goat (Capra hircus), sheep (Ovis 

 aries), wild sheep or moufflon (Ovis musimon'), bighorn (Ovis 

 montana), musk-ox (Ovibos moschatus), ox (Bos taurus), buffalo 

 (Bos bubalis), bison or auroch (Bos bison) [the buffalo of North 

 America is scarcely distinct], Cape buffalo (Bos caffer), zebu (Bos 

 indicus), and yak (Poephagus grunniens). Among the non-rumi- 

 nants are the hippopotamus (Hippopotamus amphibius), pig (Sus 

 scrofa), wild boar (Sus aper), rhinoceros [about five species ; the 

 best known perhaps is Rhinoceros bicornis, but an extinct species 

 (E. tichcrhinus) was once very common in England], tapir ( Tapirus 



