NATATORES LARID-E LESTRIS. 315 



RICHARDSON'S HAWK-GULL. 



LESTRIS RICHARDSONII. 



PLATE CXXXIV. FIG. 293. 



(STATE COLLECTION. Cabinet of H. C. De Rham.) 



Lestris richardsonii. Swainson, F. B. A. Vol. 2, p. 433. Audubon, B. of Am. Vol. 7, p. 190, pi. 452. 

 S. id. Nuttall, Man. Orn. Vol. 2, p. 319. Gieaud, Birds of Long island, p. 367. 



Characteristics. Blackish brown. Neck straw-yellow. Bill broad at the base. Tarsus 

 1 • 6. Beneath light colored. Central tail-feathers gradually tapering 

 to a point. Length, 16'0. 



Description. Bill straight, 1"2 long measured from above, 0'5 broad at the base. Tips 

 of the tail-feathers as if truncated ; the shafts slightly projecting beyond the webs. Adult 

 male : Bill bluish black : legs blacks Sooty brown above. Summit of the head dusky. 

 Quills and tail brownish black : shafts of the quills white. Young : Bill and feet bluish ; 

 outer portion of the webs blackish. Sooty brown above ; the feathers tipped with whitish. 

 Breast, sides, under wing and tail-coverts barred with dusky brown. There are, we suspect, 

 many variations in the plumage, which it may be well to describe, in order to elucidate the 

 history of this species. In the four specimens before me, from the Cabinet of the Lyceum, 

 of H. C. De Rham, and the State Collection, all of which I suppose, from the tarsus, the 

 conformation of the bill and tail, to be referable to this species, I note the following variations : 



No. 1, from Mr. De Rham's Collection : Of a nearly uniform sooty brown. Head beneath 

 the plane of the eyes, neck above and below, straw-yellow : frontlet light colored. Tarsus 

 black. Central pair of tail-feathers 8 - long. 



No. 2, State Collection : Crown, back, rump and all above brown : tips of quills and tail- 

 feathers darker ; the long subulate feathers on the nape and sides of the neck yellow. Throat 

 and upper part of the breast with an obscure brownish band, darkest on the sides. Flanks 

 distantly barred with brown. Axillaries barred with white and rufous. Lateral and under 

 tail-coverts barred with brown and rufous. Tarsi black : on one of them a broad yellowish 

 band (as in pomarinus) below the tibia. 



No. 3, Coll. De Rham : Resembles generally the preceding, but the broad belt across the 

 breast darker and more distinct. Centre of the abdomen pure white. Traces of the yellow 

 band on one of the tarsi. 



No. 4, same collection : The straw-yellow on the sides of the head brighter. Axillaries, 

 vent, upper and under tail-coverts plain brown. Frontlet with a tinge of yellow. 



I cite no history of this species, and I am unacquainted with its habits. They appear on 

 the coast of this State in winter. They are northern birds, breeding in the interior near the 

 arctic circle. 



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