524 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 49. 



Notwithstanding its great geographical range, this form appears, 

 from our material, not to be divisible into further races. It is in 

 color near Thalasseus hergii hergii, but is darker and also considerably 

 smaller. 



The Sterna hergeri of Eamsay ^ is apparently a lapsus calami, or 

 an emendation of Sterna hergii Liohtenstein,' but has for its basis 

 the Thalasseus cristatus of Gould, ^ which is the bird from Torres 

 Strait. 



The specimens of this subspecies examined measure as follows: 



Measurements of specimens of Thalasseus hergii pelecanoides. 



Museum and No. 



Sex. 



Locality. 



Date. 



U.S.N.M.219122«.. 

 U.S.N. M. 171029 <-. 



U.S.N.M. 171010 «.. 



U.S.N.M. 219121 4.. 

 U.S.N.M. 180422 4.. 



U.S.N.M. 174653 «. 



U.S.N.M. 1746524.. 

 U.S.N.M. 220199 4.. 



Male. . . 

 ...do.... 



...do.... 



Female 

 ..do.... 



..do. 

 ..do. 



Batavia Bay, Java. . 



Pulo Kelong, An- 

 amba Islands. 



Pulo Mata, Anamba 

 Islands. 



Batavia Bay, Java. . 



Tanjong Pingi, Bil- 

 liton Island. 



Pulo Laut, Natuna 

 Islands. 



do 



Welcome Bay, Ban- 

 tam, Java. 



July 11,1909 

 Aug. 30,1899 



Aug. 28,1899 



July 11,1909 

 July 28,1904 



Aug. 3,1900 



do, 



mm. 



29 



24.5 



26.5 



30 

 29 



27 



1910 



THALASSEUS BERGU RECTEROSTRIS (Peale). 



Sterna rectirostris Peale, United States Explor. Exped., vol. 8, 1848, p. 281^ 

 pi. 75, fig. 2 (Fiji Islands). 



Suhspecijic characters. — Similar to Thalasseus hergii pelecanoides, 

 but upper parts paler in both adult and young. 



Measurements. — Wing, 332 mm.; tail, 147; exposed culmen, 61; 

 tarsus, 26.5.^ Wing, 342-362 (average, 349.8) .« 



Geographical distribution. — Polynesia. Resident north to the 

 Phoenix Islands; west to the Fiji Islands; south to the Tonga 

 Islands and the Society Islands; and east to the Paumotu Islands 

 and the Marquesas Islands. 



The type of this race, described by Peale,'' is in juvenal plumage, 

 and has been mounted, but is stiU in a good state of preservation. 

 Our material, however, is not alone sufficient for the recognition of 

 Thalasseus hergii rectirostris; but Mi\ Gregory M. Mathews assures 

 me that, after again examining the series available to him, he is 

 stiU confident of its vaHdity on the characters above given. 



1 Proc. Linn. Soc. New South Wales, 1878, p. 301 . 



2 Verz. Doubl. Zool. Mus. Berlin, 1823, p. 80. 

 8 Handb. Birds Aust., vol. 2, 1865, p. 394. 



< Used in measurement averages on p. 523. 



6 One specimen, from the Paumotu Islands. 



6 Five specimens, from the Fiji; Tonga, Union, and Society Islands, measured by Stresemann. 



' U. S. Explor. Exped., vol. 8, 1848, p. 281, pi. 75, fig. 2. 



