80 Mr. E. Gibson on the Ornithology of [Ibis, 



altogether) ; sandy dunes of the Atlantic on the one hand 

 and the equally unfrequented La Plata estuary on the other, 

 and not a living thing in sight, except the ivild, clamouring 

 Gulls and the myriads of those uncanny crabs. I remember 

 it was a dull, windy day^ cold and grey, as I surveyed 

 the situation preparatory to dismounting ; and my peon 

 emphatically declined the suggestion that he should hobble 

 both the horses and accompany me. " Not if you were to 

 pay me, Don Ernesto ! And also, who is to throw the lasso 

 if you happen to get stuck in that cangrejal? ^•' Then, as 

 he saw me stripping : "For the love of God, patron, take 

 care you do not step upon a Vivora de la Cruz amongst the 

 pampa grass," The last reminder did not fail to make me 

 somewhat uncomfortable, for that very nasty pit-viper has 

 its home in the Rincones (though I have never known it to 

 be met with on our inland camp) . Such another experience 

 was in my mind, the occasion when I poached (as a boy) a 

 Black-headed Gulls' colony in Stirlingshire: a bitterly cold 

 day, and the dismal pools and treacherous bog set in a 

 bleak moor, whilst a possible gamekeeper might have 

 taken the place of the snake. 



On this date (20 October) there were about fifty pairs 

 of nesting-birds. Many of the eggs were much incubated, 

 and some young hatched out. The nests were placed at 

 varying distances apart : sometimes being mere hollows in 

 the clay; at others, placed amongst the tufts of Salicoruia, 

 a rough bedding of the same or of dry weeds. All the eggs, 

 whether fresh or otherwise, were quite unrecognisable from 

 the coating of grey cangrejal clay. The general clutch was 

 two, rarely three (no nest contained more than two young). 



The eggs are rather round in shape. Ground-colour 

 yellowish brown, spotted and blotched Avith ash-grey, dull 

 lilac, and a dark red-brown tending towards black. As 

 a rule, these markings are more pronounced and more 

 numerous towards the blunt end; but I have a specimen in 

 which the smaller end is so favoured. Taken as a whole, 

 they are rather dull-looking, as if they responded rather to 

 their surroundings than the parent-birds' bold coloration. 



The average measurement is 73 x 51 mm. 



