1905.] ON MAMMALS AND BIRDS OF LIBERIA. 197 



c. The result of this incomplete separation of the sheaths is the 



formation of a composite sheath which would presumably 

 go on increasing in length so long as new sheaths were 

 formed from the horn-core. 



d. With the exception of the first, each newly-formed sheath 



is like its predecessor in shape and length, and differs from 

 the fully and normally formed sheath of an adult animal 

 in being subconical, with the point straight, and the prong 

 either unrepresented or represented by a small wart-like 

 tubercle. 



e. The composite sheath at first grows forwards, then down- 



wards, then backwards, and is affected by a slight spiral 

 twist, causing the posterior surface of its distal extremity 

 to face the middle line. 



2. Notes on the Mammals and Birds of Liberia. 

 By Sir Harry H. Johnston, G-.C.M.G-., K.C.B., F.Z.S. 



[Received March 21, 1905.] 



Liberia, as seen on the map, is little more than the southern- 

 most prolongation of the legion which might be styled Northern 

 Guinea. The southernmost point of Liberia, at the mouth of the 

 Oavally River, is the most southerly extension of the true West 

 Coast of Africa. At this point the West Coast reaches to within 

 little more than 4 degrees of the Equator. Although this 

 country is not marked off. clearly by any natural features either 

 from Sierra Leone on the one hand or the Ivory Coast on the 

 other, it possesses a certain distinctness and a slight degree 

 of peculiarity as regards its flora and fauna. The botanical 

 collections that have been made by those v/ho have been working 

 with me recently in Liberia have brought to light several 

 genera and a large number of new species of plants which appear 

 to be restricted in their distribution more or less to the political 

 limits of this Negro republic. I do not think that quite the same 

 degree of peculiarity can be ascribed to the fauna even amongst 

 vertebrates, which offer the greatest amount of specialisation or 

 exclusive distribution. As regards mammals and birds, Liberia 

 is to a great extent a meeting-place for the forms of Northern 

 Guinea (Sierra Leone to the Gambia) and those of the Gold Coast,, 

 the Niger Delta, and the Cameroons. Some types find Liberia 

 their northernmost or westernmost limit of range from the Congo 

 Basin, the "Victoria Nyanza, and the Bahr-el-Ghazal. Of such 

 may be noted, besides various birds, the Bongo Antelope, which 

 is found abundantly in Liberia, but which does not, I believe, 

 extend its range much to the west of that country. Also the 

 Red Congo Buffalo. I fancy I am correct in saying that this type, 

 the horns of which I have seen in the interior of Liberia, does 

 not differ from the Red Buffalo of the Congo, but that it scarcely 



