1 91 8.] Cape San Antonio, Buenos Aip'es. 405 



These were exceedingly shy and silent ; but my oppor- 

 tunities were too limited for extended observation. In the 

 course of past years, I was aware of having rare glimpses 

 of a bird which could only have been of this species, but its 

 wildness and swiftness had hitherto always baffled my being 

 sure of the identification. 



171. Milvulus tyrannus (Linn.). Scissor-tailed Tyrant. 



Such a striking species as the Scissor-tail is sure to have 

 its habits fully described, r.nd consequently my former paper, 

 along with that of Mr. Hudson and Mr. Grant's notes, 

 affords a fairly complete account of what is known. 



Its earliest chronicled appearance in Ajo is, I find, on 

 11 October ; but it does not become abundant until the end 

 of that mouth. The last departure occurs towards the end of 

 March. I agree with Mr. Grant that the spring immigration 

 is initialed by the males, but the rule is not absolute ; for, 

 on one occasion, whilst lying becalmed in a sailing-ship on 

 a sunny morning off the town of La Plata, on 17 October, 

 I noted the advent of a pair, flying low, coming from the 

 Banda Oriental, and which were subsequently followed by a 

 single male. In the summer of 1913-14, when our dis- 

 trict was so gi'eatly flooded, the species was extraordinarily 

 abundant. 



The nesting-notes require no addition, beyond the recti- 

 fication of my former dictum that the number of eggs 

 never exceeded three ; as a matter of fact, four is not 

 uncommon. These have been fully described. They 

 measure 2.2 x 16 mm. 



176. Geositta cunicularia (Vieill.). Common Miner. 



" Send me some eggs of the Common Miner,^' was the 

 request of Dr. Eagle Clarke, on behalf of the Edinburgh 

 Museum, a good many years ago. Alas, the Miner is 

 common no longer in this particular district. As 

 described in the present notes on the Bank - Swallow 

 (Atticora cyanoleuca), the extermination of the Biscacho 

 [Lagostomus trichudactylus) on these level and bankless 



