Horn of Africa periodic monsoon winds and irregular rainfall. Mean daily maximum temperatures range from , except at higher elevations along the eastern seaboard, where the effects of a cold offshore current can be felt. Somalia has only two permanent rivers, the Jubba and the Shabele, both of which begin in the Ethiopian Highlands. About 220 mammals are found in the Horn of Africa. Among threatened species of the region, there are several antelopes such as the beira, the dibatag, the silver dikdik and the Speke's gazelle. Other remarkable species include the Somali wild ass, the desert warthog, the hamadryas baboon, the Somali
Gates of horn and ivory that of horn as the passageway for true shadows and that of ivory as that through which the Manes in the underworld send false dreams up to the living. Through the latter gate Virgil makes his hero Aeneas, accompanied by the Cumaean Sibyl, return from his visit to the underworld, where he has met, among others, his dead father Anchises: Two gates the silent house of Sleep adorn; <br>Of polish'd ivory this, that of transparent horn: <br>True visions thro' transparent horn arise; <br>Thro' polish'd ivory pass deluding lies. <br>Of various things discoursing as he pass'd, <br>Anchises hither bends his steps