HALIPLANA DISCOLOR. 
ROCKY BIRD. 
STERNA PANATA. Lath. Ind. Om, Yol. II., p. 808. 
HALIPLANA PAN A YEN SIS. Salvin. Ibis., 1864, pp. 381 and 385. 
HALIPLANA DISCOLOR. Coues. Ibis., 1864, p. 392.— Lawk. Ann. Lyc. Nat. Hist., N. Y., Yol. YIII , p. 104. 
This Tern is an inhabitant of the West India islands and the sea-coast of British Honduras, and is included among the birds of 
North America from the fact of one specimen, now in the collection of Mr. Geo. N. Lawrence, having been obtained by Mr. Audubon, 
on the coast of Florida, where it is doubtless however only a straggler. In the article quoted above, Mr. Lawrence gives the follow- 
ing account of this bird, furnished him by Mr. A. A. Julien, who observed it on the island of Sombrero, AY. I. : 
“Egg bird. So called I presume, from the abundance of the eggs derived from it; for I am inclined to believe that in former 
years the number of individuals visiting this Key has been surpassed only by that of the Noddy and Royal Tern. It is peculiar 
especially for its social habits in regard to the Noddy ; whatever may be its numbers upon the Key, it is almost always to be found in 
the flocks of Noddies. They arrive in March and depart in August. This species makes its nest about after the same fashion as the 
Noddy, and lays but one egg. It often flies high with a noisy chatter, very different from the discordant 'caw, caw' of the Noddy, 
and a quick darting motion. I have never noticed the two species to quarrel, though the individuals of both will often fight long 
and obstinately with each other.” 
Salvin, in his very interesting communication to the Ibis on the sea-birds of British Honduras, gives a short account of this bird. 
“Remembering the Terns we had left the previous day about the old snags on the reef, I returned in the schooner to Saddle Cay, 
shooting a specimen of Thalasseus acuflavidus by the way. At Saddle Cay we found a fresh arrival of Terns and Laughing Gulls 
{Laras atricilla). The former all belonged to a second species of Sooty Tern (. Ilaliplana panaya). No time had been lost by the 
Terns, for on searching the Cay we found four eggs had already been laid. A little sand was scratched away for a nest, under such 
shelter as the bushes that grew nearest the beach afforded. This ifaUplana is known to the Creoles as the “Rocky Bird.” It is a 
very graceful species, though its flight is rather heavy for a Tern, not having the same dash about it that so strikes one on watching its 
congener, H. Fuliginosa. The eggs are rather less ruddy and smaller than those of the commoner species, but similar in other respects.” 
Dr. Coues has separated this bird from the well-known H. Panayensis Gmel, and Mr. Lawrence sustains him in so doing, while Mr. 
Salvin takes exception to this proceeding, and considers that this bird is identical with the species from Australia, etc. 
I have examined the type H. Discolor and other specimens from similar localities, with the example of H. Panayensis, figured in Gould’s 
Birds of Australia, and which is now in the Academy of Natural Sciences of Philadelphia, and find the following slight differences: 
H. Panayensis has the back dark brown. Inner-web of outer tail-feather, brown for half its length, and the outer web for about 
one-third ; remainder white. Rest of tail-feathers brown, light at base. 
H. Discolor. Type, has the back brownish-grey. Outer tail-feather pure white for its entire length, next dark brown on inner web 
for about an inch from the tip, remainder white. The third is brown for half its length, white at base. Rest of the feathers brownish 
grey, light at base. 
It will thus be perceived that the specimens to which Dr. Coues -has given a separate specific name, are rather lighter in color than 
those of Mr. Gould, and rather differently marked upon the tail-feathers. But I must farther state that all the specimens of LI. Discolor 
did not entirely resemble the type, for in some the outer tail-feather, instead of being pure white, was blackish-brown on the inner web 
for about one and a half inches from the top. 
I have represented the bird as H. Discolor, and have thus given Dr. Coues the benefit of any doubt there may exist upon the sub- 
ject, but in view of the very slight differences existing between the representatives of the species from the different localities in which 
they are found, all of which have been included in the comparison given above, it would seem that the characters are hardly sufficient 
to constitute a specific distinctness, particularly as some of them do not appear to be constant, and that it will probably be far better 
to consider the two birds as but one species ; the H. Panayensis. 
I am indebted to Mr. Lawrence for the loan of his specimen to be figured in this work. 
Crown, nape, and lores black; front, line over the eye, cheeks and throat white; upper parts brownish-grey; wings sooty brown, 
primaries brownish-black. Tail like the back, outer-feather white, rest as described above. Under parts white washed with grey. Bill, 
feet, and tarsi, black. 
The figures. are life-size. 
