during a Cruise in the Caribbean Sea. 333 



Tip of bill pale greenish white, horny white, or pearly 

 green. 



Feet and tarsi bright crimson, claivs brown. 



COLUMBA CORENSIS Gmcl. 



Although I did not secure any examples, I was told that 

 a second Pigeon was found on the island, and from the 

 description given me I concluded it to be this form. 



SuLA suLA (Linn.). 



Nesting in quantities on the easternmost of the two 

 islands. 



Young birds just able to fly are entirely/ brown; webs and 

 feet dirty yellow. Bill slaty grey, not yellow at base. Irides 

 pearly grey. 



Some of the nests on this island were made with a 

 foundation of twigs and were lined with sea-grape leaves, 

 wdiile others were merely depressions in soft beds of a 

 Mesembryanthemum-Wke plant which covered the rocks 

 near the shore. The island swarmed with iguanas, which 

 were crawling about among the young Gannets. 



SuLA piscATOR (Linn.). 



Many of these birds were nesting on the eastern island 

 at the time of our visit. 



Fregata aquila (Linn.). 



A large colony of these birds was breeding on the eastern- 

 most of the two islands, and, contrary to what obtains on 

 the Los Hermanos group, the nests were placed on the tops 

 of fairly tall trees about twenty-five to thirty feet high, in 

 some cases as many as eight or nine being found in one tree. 

 The alarm-note (if such it is) of this bird while on its nest is 

 peculiar, being a series of rapidly repeated half -guttural 

 half-whistling sounds, very difficult to describe. While 

 uttering these sounds the mandibles are alternately and 

 rapidly opposed and separated, the interramal space being 

 slightly distended. When alighting on its nest the Frigate- 

 bird is extremely clumsy, and, if flurried, will often slip 



