DOLICHONYX.—MOLOTHRUS, 449 
Swainson, who states that Bullock’s specimens submitted to him were obtained on the 
tableland 2. In Yucatan and the islands of the east coast of British Honduras D. ory- 
zivorus seems to be much more numerous, Mr. Gaumer having procured many examples. 
It was on this coast too that Salvin met with it on a small coral islet at the northern 
end of Lighthouse Reef, one of two islands called Northern two Cays; this was on the 
20th May, 1862, a very late date for the occurrence of individuals so far south. 
It also occurs in Costa Rica, its name being included in Mr. Zeledon’s list, but it is 
not mentioned by other writers on Costa-Rican birds. In the State of Panama it has 
frequently been observed. We thus seem to trace the western limit of the line of the 
migration of this species. In passing southwards the western flocks do not, as a rule, 
go further westwards than the promontory of Yucatan ; thence they follow the coast-line 
southwards to Panama, and then spread at large over the continent of South America, 
The eastern border is not so definite. D. oryzivorus is recorded from the Bahamas and 
from Grenada, but it is rare in British Guiana; a large number of birds, therefore, 
probably cross the Caribbean Sea from Cuba and Jamaica direct to the mainland of 
South America. 
In their spring migration Dr. Gundlach tells us the male birds arrive in flocks apart 
from the females, but that in autumn the sexes all associate together. 
As already stated, the males lose their dark plumage after the breeding-season and 
assume the female dress, which again is changed at the approach of spring. 
Dolichonye oryzivorus makes a flimsy nest of dried grasses on the ground, and lays 
four or five eggs of a dull bluish-white colour, sometimes brownish-white spotted and 
blotched with dark chocolate or blackish-brown surface-marks and others of paler 
colour in the shell }, 
The notes of this species are described as very pleasing, many males often singing 
together. 
MOLOTHRUS. 
Molothrus, Swainson, Faun. Bor.-Am. ii. p. 277 (1831) ; Coues, Key N. Am. B. ed. 2, p. 401; 
Scl. Cat. B. Brit. Mus. xi. p. 332. 
Mr. Sclater, in his recent catalogue of the Icteride, includes nine species of Molo- 
thrus which are distributed over the greater part of America, the bird of the northern 
continent (Molothrus pecoris) extending from Canada southwards and Molothrus bonari- 
ensis of the southern continent reaching the Straits of Magellan. Two species occur 
within our region—the northern UV. pecoris in both its forms occurring over the greater 
portion of Mexico; M. ewneus, on the other hand, is found throughout our region, and 
crosses the Rio Grande into Texas. 
The curious habit of all members of this genus of the females laying their eggs in 
other birds’ nests, and leaving the duties of incubation and rearing their young to foster- 
parents, has been very fully described by various authors—one of the most interesting 
BIOL. CENTR.-AMER., Aves, Vol. I., February 1887. 57 
