402 ZOO-GEOGRAPHICAL NOTES.

look for true steppe birds in the eastern division of our country, although we shall also meet with forms which have hitherto been known as belonging exclusively to the east. Among the former, the ostrich ought to rank first; it is always found wandering about in flocks, of often thirty birds; it keeps strictly to the steppe, especially where covered with brushwood, and avoids altogether forest, mountain lands, and damp tracts. From the class of birds of prey it may suffice to select Melierax polyzonus, Riipp.; LHelotarsus ecaudatus, Daud.; and Poliornis rufipennis, Strickl., the last of which has its proper home here.

IT am astonished at never having yet met with the bird of the steppe par excellence, Gypogeranus serpentarius, L., though I have no doubt of its existence here. As a matter of course, all the birds dwelling in the steppe region farther to the north frequent also our southern steppes, and therefore no special enumeration of them is necessary, for they consist for the most part of forms widely distributed over Africa, Turning to the purely eastern varieties, we first of all come across Schizorhis leucogastra, Riipp., which even in Latuka replaces Schizorhis zonura, Riipp. (a native of all other parts), and is the prevailing form far down to the south (Uganda). Its western limit may be laid down at 32° 30’ E. long. The following are also purely eastern birds:—Dryoscopus mgerrimus, Reich.; Spermestes caniceps, Reich.; Crithagra chloropsis, Cab.; Caprimulgus inornatus, Heugl., all of which are caught in Latuka. It must further be remarked that none of these eastern species cross to the western side of the Bahr-el-Jebel valley ; on the contrary, several do not even reach it, but confine themselves to the eastern slope of the mountains of Obbo.

The circumstances connected with the flora and fauna of the western side of the river do not assume such a simple form. As already stated, there is here also a chain of mountains running from the lake towards the north, at a greater or less distance from the river. At about 4° 8’ N, lat. this range leaves the river, and, gradually decreasing in height, runs in a north-westerly direction to the Bahr-el-Ghazal; all the country lying to the north and east of this chain, consequently the whole triangle formed by it, the Bahr-el-Ghazal, and the Bahr-el-Jebel, belongs to the steppe domain, and the fauna assumes a corre-