UNGULATA. 369 



thickened and penetrated by air-cavities, while when frontal 

 appendages are present, these (or at least one pair of them) 

 are small bony prominences, separately ossified, which are not 

 shed but eventually become fused with the skull and are 

 always covered with skin. The upper canines are absent and 

 the molars are brachyodont. The lateral digits of the limbs 

 are entirely wanting or represented only by the upper end of 

 the metapodials. 



In the existing giraffe (Giraffa or Camelopardalis) the pair 

 of bony prominences is placed over the suture between the 

 frontal and parietal bones, and is covered with hairy skin ; the 

 armature is present in both sexes and even in the newly-born 

 young. It is not yet certain, however, whether the early 

 Pliocene animal with equally long neck and limbs and similar 

 teeth, was characterized by horns of the same disposition, and 

 may therefore be placed in the same genus ; for the only known 

 remains from China, from the Siwalik Formation of India 

 (Giraffa sivalensis, G. affinis), and from the well-known mam- 

 maliferous deposit of Pikermi in Greece (G. attica), are very 

 fragmentary and do not include the top of the skull. The 

 best-known extinct giraffe, of the same early Pliocene period, 

 undoubtedly belongs to a distinct genus, named Samotherium 

 from the discovery of the finest specimens in the Isle of Samos 

 in the Turkish archipelago. In this animal the neck and limbs 

 are somewhat shorter than in the surviving Giraffa, and the 

 horns are confined to the male sex. The horns, moreover, are 

 fixed entirely on the frontal region directly above the orbits 

 (fig. 209); and the same arrangement is observed in a fine 

 skull of Palceotragus from the Pikermi deposit, which was 

 originally supposed to belong to an antelope but is now regarded 

 as more probably giraffine. An imperfect skull from the Lower 

 Pliocene of Maragha, Persia, also seems to be referable to 

 Samotherium. 



Samotherium is about as large as an ordinary giraffe, but 

 the extinct genera exhibiting shorter neck and limbs and a 

 more bovine aspect, comprise much larger species of remarkably 

 stout proportions. Helladotherium, from Pikermi, is known by 

 a hornless skull about 075 m. in length, and by the greater 

 w. 24 



