132 



have at present two male examples of this bird in the Gardens. 

 Last summer, along with the Secretary-birds (Serpent arius reptili- 

 vorus), came two Spur- winged Geese from Eastern Africa. They 

 were placed in the Gardens along with the W. African pair, and 

 immediately attracted the notice of those who take an interest in such 

 matters, as being apparently of a different species. Comparing the 

 males of the eastern and western birds together, we observe that 

 the former is larger, stands considerably higher, and has longer 

 tarsi and larger feet. There is a large oblong naked space of bare 

 pink skin on the throat, which is wholly wanting in the West 

 African bird ; the beak is longer, and the bony protuberance on the 

 front is much larger and more elevated. We have not, unfortu- 

 nately, the female of the eastern species ; but Ruppell tells us that 

 in her too there is a stripe of naked skin between the eye and the 

 base of the bill. Now in the western bird the whole sides of the 

 head in both sexes are closely feathered : the male has a frontal pro- 

 tuberance (much smaller, however, than in the eastern species) ; the 

 female has none. It appears therefore that two species have been 

 confounded together under the name gambensis. The West African 

 bird, originally brought from the Gambia (whence the name), and 

 which has been described and figured as such by Latham, Yarrell, 

 and other writers, is obviously the proper owner of the title Plec- 

 tropterus gambensis ; while the East African bird, first accurately 

 figured and described by Dr. E. Riippell in the third volume of the 

 ' Museum Senckenbergianum,' may very appropriately take the name 

 of Plectropterus ruppellii. 



On examining the stuffed specimens in the gallery of the British 

 Museum, as I have been enabled to do through Mr. G. R. Gray's 

 kindness, I find examples of both species. Of the larger Plectro- 

 pterus riippellii there is a male bird procured during Clapperton's 

 expedition in Central Africa, and a female which died in the Zoolo- 

 gical Gardens. Of the smaller Plectropterus gambensis there is one 

 from Western Africa, and one of which the locality is not marked. 

 An immature bird from the Cape is certainly referable to the smaller 

 species. 



The separation of these two birds may not perhaps be entirely 

 satisfactory until we have had an opportunity of examining their 

 internal structure, several parts of which, particularly the trachea, 

 are well known to afford good characters for discriminating nearly 

 allied species among the Anatidce, as has been so successfully shown 

 in Mr. Ey ton's Monograph. 



In the accompanying plate (PI. CLIII.) are represented the male 

 birds of Plectropterus gambensis and Plectropterus ruppellii. 



