326 MR.W. H. HUDSON ON THE BIRDS OF BUENOS AYRES. [May 2, 



to be restricted to Abyssinia and Sennaar so far south is certainly a 

 noteworthy although not unprecedented fact. 



Sternum of Pelomedusa from the Zambesi (nat. size). 



" On the Lower Zambesi Dr. Peters found P. galeata, the common 

 species of the Cape Colony (with which P. nigra, Gray, of Natal, is, 

 in my opinion, identical*) abundant." 



The following (twelfth f) letter on the ornithology of Buenos Ayres, 

 addressed to the Secretary by Mr. W. H. Hudson, C.M.Z.S., was 

 read : „ Buenos AyreSj September 22, 1870. 



" Dear Sir, — As I have so far always made tbe species that in- 

 terested me most at the moment of writing the subject of my letters, 

 I will now say something of the Swallows of this country ; for these 

 ever welcome little emigrants are at present hourly arriving and scat- 

 tering themselves far and wide over the plains of Buenos Ayres. 



* See also Strauch, M£m. Ac. St. Petersb. ser. 7, vol. viii. p. 111. 

 t See anteh p. 258, for eleventh letter. 



