50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



height of maximum storm waves, others higher, I estimated that 

 the colony consisted of 30 to 35 pairs. Scattered birds rested on 

 the water in addition to those that perched on the cHffs, or circled near 

 the island. 



The eggs are oval, some broader than others, verging toward 

 short-oval. The shell is pitted, and the ground color is dull white, 

 but in most so solidly dotted with Natal brown to bone brown that 

 the lighter base is almost completely obscured. In some the dots 



Fig. 9. — Red-billed tropicbird, rabijunco, Phaethcni aethereus mesonauta. 



are more concentrated at the larger end, and occasional eggs have 

 scattered irregular spots, or are less heavily marked so that the 

 pale base color is seen. Bent (U. S. Nat. Mus. Bull. 121, 1922, p. 188) 

 gives the measurements, taken from 40 eggs, as ranging from 50.5 

 to 63.2 mm. long by 36.5 to 46. mm. broad, with the average 56.4 by 

 41.7 mm. 



This is the only colony in the western part of the southern Carib- 

 bean Sea, the nearest known neighbors of the species being on Los 

 Roques off the north coast of Venezuela, 1,600 kilometers distant. 

 There has been some confusion in published accounts as to the 

 location of Swan Cay. Peters (Bull. Mus. Comp. Zool., vol. 71, 



