472 Mr. C. H. B. Grant on Birds collected in Argentina, 
dashing continually past ns within a few feet, while their 
combined cries were so deafening that we could hardly hear 
each other speak. 
The nest is a mere hollow in the open sand, and three eggs 
seem to be the complete clutch, but many birds lay only two, 
and quite a number of eggs were scattered about the bank, 
rotten and often half covered with sand. 
There were also a few nestlings of all three species, and on 
Oct. 26th, when we visited the same bank on the return south, 
breeding was practically finished, and numbers of young were 
just on the wing. 
At one bank visited on Sept. 24th, fair numbers of both 
the Terns and the Skimmers were breeding, but only one 
pair of Sterna superciliaris, having two young just flown. 
A great number of the nesting hollows were empty, and 
we shortly discovered the reason why, for under a large 
piece of dry wood we saw and shot a large snake, which, 
on being cut open, contained one adult and two young of 
P. magnirostris. 
Fifty eggs were brought home, taken at Colonia Risso, 
Sept. 9th, near Puerto Braga, Sept. 24th, and Colonia Risso, 
Oct. 26th. The majority of these agree with the description 
given by Mr. Oates in the Catalogue of Eggs, but some have 
the ground stone-colour, and one set are of a yellowish olive. 
They also vary greatly in the markings, some are evenly 
marked all over as described in the Catalogue, others have 
the greater number of: the markings at the larger end, often 
forming a zone ; some are finely spotted and blotched, and 
these have the markings broad and often of a deeper brown 
than that described in the Catalogue, i. e. of a yellowish 
brown and pale purple. They measure : axis 1’85 to 2T in., 
diam. 1*4 to 1*5. 
265. Sterna maxima. 
Sterna maxima Arg. Orn. ii. p. 195 ; Saunders, Cat. B. xxv. 
p. 80. 
a. <$ ad. Tuyu, Aj<5. Mar. 1, 1910. 
This specimen is in full winter plumage. During the week 
