112 Bulletin American Museum of Natural History [Vol. XLIII 



Mediterranean is distinctly palsearctic, the fauna of the lands lying 

 south of the Sahara and traversed by the great river sj^stems of the con- 

 tinent is more nearly related to the Indo-jVIalaysian fauna, but pos- 

 sesses a number of genera and species which occur nowhere else upon the 

 globe. Beginning in the southern part of Senegal, in latitude 12 ° N., 

 and extending eastward and southward to the headwaters of the various 

 affluents of the Congo and the Coanza, there is a more or less densely 

 forested region, thoughout which the flora and fauna with slight modi- 

 fications are practicalh^ the same. Southern and eastern Africa are char- 

 acterized by the presence of great expanses of grass-land, save along the 

 watercourses. This territory, in which there is more or less aridity, 

 extends northwest from the region of Uganda and thence west about the 

 headwaters of the various rivers flowing into the Atlantic south of the 

 Sahara, forming a selvage between the hot densely forested jungle- 

 lands to the south and the dry desert-lands to the north. Here and 

 there the forested country is interrupted, as in Angola and various points 

 along the western coast, by smaller tracts where the forests are less 

 luxuriant and open grass-lands occur. The lepidopterous fauna of the 

 grass-lands, which until the end of the last century have been the home 

 of vast herds of ruminant animals, reveals the predominance of certain 

 genera, such as Teracohis, which are characteristic also of Abyssinia, 

 Arabia, and southern India. The humid jungles along the Coanza, the 

 Congo and its tributaries, the Ogove, the lower Niger, and the various 

 rivers emptjdng into the Atlantic from Lagos to Dakar are the home of a 

 fauna which by common consent is known as West African. Here is the 

 metropolis of the African Nymphalidae, of various mimetic forms of 

 Lj^csenidse belonging to the genera of the subfamily Lipteninae and of 

 various genera of the Hesperiidse, which are found nowhere else upon 

 the globe. Here and there this great forest region is invaded on its 

 eastern and northern borders by inwardly projecting stretches of the 

 surrounding grass-lands, and there is thus noted a transition on its 

 periphery from the West African fauna to the South African or East 

 African fauna. In fact, the East African fauna and South African fauna 

 reappear on the north and northwest of the irregular territory in which 

 the West African fauna occurs. At the very mouth of the Congo there 

 occurs in the region of Matadi an intrusion into the West African region 

 of some forms which may properly be considered as characteristic of 

 the South and East African fauna. 



The largest portion of the collection returned by the American 

 Museum Congo Expedition was obtained at Medje, a point near the 



