I918.] Cape San Antonio, Buenos Ayres. 383 



of a pair of Swallows having taken up their abode in the 

 skull of a whale is somewhat reminiscent of the anachronism 

 of Samson's beehive in the dead lion ! 



Four or five eggs is the general number of a clutch (only 

 once have I seen six). These are pure white^ of an elon- 

 gated pear-shape, and average 21 x 14. mm. 



30. Atticora cyanoleuca (Vieill.). Bank-Swallow. \'^'^^^r^ 

 The Bank-Swallow has, to all practical jjurposes, passed 

 beyond my ken for the last thirty-five years. It is still to be 

 seen occasionally in the district (see Ibis, 1911, p. 92). But 

 in remarking that "it does not now breed in the Ajo district, 

 or if so very sparingly/' Mr. Grant omits to furnish the clue 

 to his statement. Mr. Hudson describes how the species was 

 common on the level Pampas because it took possession of 

 the forsaken hole excavated by the little Miner (Geositta 

 cuniculuria) in the brow of the Vizcacha or Biscacho's 

 burrow. Now it so happens that many years ago there 

 was carried out a systematic extirpation of Vizcacha {Lago- 

 stomus trichodactylus), with the result that nowadays, to 

 take oui own Estancia, a Vizcacha is as likely to be found 

 as the extinct Red Wolf or Aguaia Guazii {Canis jubatus), 

 whilst their erstwhile innumerable villages are fallen in 

 and assimilated completely to the surrounding grass plain. 

 With the Vizcacha went the Miner (for it found no little 

 bank of any kind to excavate in, except an occasional bunker 

 in the sand-hills); and without the Miner the Bank-Swallow 

 lost the landlord in whose flat it had a reversionary interest. 

 In the foregoing is another curious instance of the eflects 

 produced in the chain of Nature by tampering with one 

 of its links or factors. [In my 1879 paper I erroneously 

 alluded to this specie^s as Hirundo leuconhoa.] 



The nest is placed in the chamber at the end of the 

 passage or burrow, is built of dry grass, and lined with soft 

 feathers. The eggs (of which I have taken five to the 

 clutch) are laid towards the end of October ; they are 

 pure white and pointed. Unfortunately 1 do not possess 

 the measurements. 



