NATATORES. 



363 



the much smaller size than either of the preceding being its essential 

 distinguishing character. Under date of July 19th, lat. 13° 38' S., 

 long. 89° 24' W., we find the following in Dr. Pickering's Journal : 

 "At lOi A.M. two Frigate Birds were seen, which appeared desirous 

 of alighting, but after hovering around the Vincennes and the Por- 

 poise for some time, disappeared. We saw nothing of this bird at Cal- 

 lao, nor at Valparaiso, and were at a loss to conjecture where they 

 could have come from, as we had only heretofore noticed it in the 

 vicinity of land. The species seemed to be different from the Bra- 

 zilian, and smaller. The head and under parts of the body white in 

 both specimens. Nearest land 660 miles." 



The small species alluded to above as Tachypetes Ariel, Gould, is 

 very probably the same as Pelecanus minor, Gmelin. 



3. Genus SULA, Brisson, Orn. VI, p. 495 (1760). 

 1. SuLA FIBER {Linn.). — The Brown Gannet. The Booby, 



Pelecanus Fiber, LiNN. Syst. Nat. I, p. 218 (1766). 



Pelecanus Sula, LiNN. Syst. Nat. I, p. 218 (1766). 



Pelecanus parvus, Gm. Syst. Nat. I, p. 579 (1788)? 



Sula/usca, Vieill. Gal. II, p. 194 (1825). 



Sula brasiliensis, Spix. Av. Bras. II, p. 83 (1825). 



Sula austrah's, STEPHENS, Gen. Zool. XIII, p. 104 (1826). 



HEAD OF TACHYPETES PALMERSTONI, 



Catesby's Carolina, Plate LXXXVII; Vieill. Gal. II, Plate 



