Vol. xliii.] 64 



Black-billed Cuckoo {Coccyzus melacoryplms). 



The sets shown, 2/2, 1/3, were also collected at " Los 

 Alfalfares " iu 1907, nests being placed in low scrubby 

 bushes, constructed of twigs, very small for the size of the 

 bird and rather flimsy, but rounded and hollow, and not 

 shallow like a Dove's nest. Shape elliptical ; colour dull, 

 spotless, very light bluish green. Average measurement 

 2-95 X 2-60 cms. 



Cinereous Cuckoo {Coccyzus cinereus). 



The 2/3, 1/2 eggs of this species (there is reason to believe 

 the first to be discovered or brouglit to this country) were 

 collected at the Estancia "La Ethel," Buena Esperanza 

 Province of San Luis, in Dec. 1912, and parent birds 

 identified by close comparison with the coloured plate in 

 'Argentine Ornithology,' vol. ii. p. 38. 



The three nests found were all contemporaneous and in 

 the same neighbourhood — a tract of wild undulating un- 

 cultivated land covered with coarse native grass and scattered 

 clumps of short chaiiar thorns. They were all exactly 

 similar and small for the size of the bird, about 5 inches 

 across, of fine twigs ratlier compactly woven together, with 

 depression only slightly more pronounced than that of the 

 small Doves, which, in outside structure, they closely 

 resen)bled. 



All three were lined alike with long, dry, thin, soft stripes 

 of whitish-green vegetable fibre, which gave them a singular 

 and characteristic appearance. 



They were placed in chanar thorns, from 2 feet 6 inches 

 to 3 feet 6 inches from the ground, and not well concealed, 

 as the first one found was detected quite easily when riding 

 round the thorn on horseback. The eggs arc a dull lustre- 

 less white, elliptical in shape, the sliell thick for their size, 

 very hard, and in texture close-grained. Average measure- 

 ments 2'55 X 2"05 cms. The eggs of the two sets of thi-ee 

 showed incubation in very different stages, and would be 

 ap[mrently laid at considerable intervals — 4 or 5 days at 

 least, judging from the difference in size of the embryos. 



These two clutches wore advanced in incubation, and 



