588 UNGULATA. 



canines are incisiform, p ^ m §, the premolars secant ; molars seleno- 

 dont ; the naviculai", cuboid and ectociineiform bones are united. The 

 psalterium of the stomach is reduced to a tube. Blood corpuscles ysioo in- 

 in diameter. 2 Uving genera, S. Asia and Africa ; an ancient family, 

 known since the Eocene. They are in many respects intermediate between 

 the Ruminants and the other Artiodactyls, the stomach, placenta and feet 

 recalling the latter. Tragulua Pall., smallest living Ungulate, 3 species 

 from the Malay Peninsula, 1 from Ceylon and India, 1 species in the 

 Pliocene. Hyomoachus Gray {Dorcatherium), 1 species, the water-chevro- 

 tain, from W. Africa. Extinct genera, Lophiomeryx Pomel, Eocene, 

 France ; Oelocus Aymard, INIiocene, France, sometimes placed with the 

 Xiphodontidae ; Dorcatherium Kaup, Miocene, Evirope and Asia. 



Pecora (Cotylophora).* 



Skull usually with horns containing a bony core * § c '—— p § m f ; 

 lower canines as incisors ; premolars simpler than molars ; odontoid 

 process crescent-shaped ; molars brachydont or hypsodont ; with closed 

 orbit ; a vacuity between the nasal, lacrymal, frontal and maxilla (absent 



in sheep and oxen) ; 

 large lacrymals, 

 often with a depres- 

 sion, the suborbital 

 or lacrymal fossa ; 

 tympanic not fused 

 to periotic ; bulla 

 small without can- 

 cellous tissue ; large 

 paroccipital process. 



Fig. 307.-flkQll of Cervus canadenstt. ^^^^ reduced, fixed 



behind the radius ; 

 fibula reduced to the malleolar bone which articulates with the lower 

 end of the tibia ; metapodia of digits 3 and 4 anliylosed into a 

 cannon bone, those of 2 and 5 never complete and often absent 

 together with the reduced digits ; navicular and cuboid coalesced. 

 The stomach has four complete chambers. The placenta is cotyledonary. 

 The Pecora are entirely absent from the Australian region, and there are 

 comparatively few living forms in the New World. Bovidae are entirely 

 absent from the Neotropical region and there are only four genera in the 

 Nearctic. Living Cervidae are entirely absent from the Ethiopian region. 

 Fam 11. Cervldae.f Deer. Horns when present have the form of 

 antlers. They consist of bony processes of the frontal bones covered 

 during their growth by a soft vascular velvety skin. They are found in 

 the male only, but in the reindeer they occur in both sexes. They are 

 absent altogether only in Moschus and Hydropotes. They are shed each 

 year after the rutting season and grow again with great rapidity in the 

 following year. When they have attained their full size a circular ridge 

 — the burr — is formed round the base at a short distance from the skull, 

 and the ' velvet ' gradually dries up and is rubbed off. Later absorption of 

 bone takes place on the proximal side of the burr and the antler is shed. 



* A. H. Garrod, Proc. Zool. Soc. 1877, p. 2. 



t Rutimoyer, Beitr. Nat. Gescliichte d. Hirsche, Ahh. Schweiz. paldont. 

 Gcs. 7, ISSO ; 8, 1881 ; 10, 1883. Lydekker, Deer and their Horns, 1898. 



