106 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



was taken on Hood, September 28, 1905, and eggs and young 

 in early February, 1906. On Hood I took a bird and a fresh 

 egg from a nest, in which five days before a pair of Swallow- 

 tailed Gulls held sway. Many tropic-birds were occupying 

 nests the owners of which had been killed less than a week 

 before. These facts give some idea of the great demand for 

 nesting sites on southeast Hood. At Onslow Island on Febru- 

 ary 25, I noticed two birds in holes in a rock about twenty 

 feet above the water, and I also saw a bird enter a hole. 



On the voyage south from San Francisco we first met with 

 the Red-billed Tropic-bird to the west of San Martin Island, 

 Baja California, on July 9 and 10. We again saw one on 

 July 22 in latitude 22° 25' North, longitude 112° 40' West. 

 At San Benedicto, Revilla Gigedo Islands, they were fairly 

 common, and we saw some in holes in cliffs over the ocean. 

 On the coast of Ecuador, in the vicinity of Manta, on Septem- 

 ber 18, 19, and 20, we saw several. So all in all, it did not 

 prove a common species at sea on the voyage from San Fran- 

 cisco to the Galapagos Islands. 



On the homeward voyage from the Galapagos, we saw 

 single birds on seven occasions, beginning on September 28, 

 1906, in latitude 7° 23' North, longitude 97° 48' West, and 

 ending on November 4, in latitude 26° 50' North, longitude 

 126° 47' West. 



In life, the adults have the bill of a crimson color; outer 

 part of toes and webs black; tarsi and inner part of toes and 

 webs ochraceous buff; under sides of toes and webs pearl- 

 gray. The bills of the unfledged young are grayish and yel- 

 lowish, while the bills of the fully fledged young are a distinct 

 yellow. 



An examination of the Academy's series of adults from the 

 Galapagos Islands shows specimens from Daphne in Novem- 

 ber, which are apparently just completing a postnuptial moult, 

 as testified by new and growing primaries. The same remarks 

 apply to a specimen taken at Hood in February. 



From the measurements given below, it appears that the 

 sexes are evenly matched in size. The long tail-feathers, 

 however, are so subject to wear and tear that it is doubtful 

 if any one measurement represents the total length of the 

 longest tail-feather in an absolutely perfect state. Of the 



