during a Cruise in the Caribbean Sea. 333 
Tip of bill pale greenish white, horny white, or pearly 
green. 
Feet and tarsi bright crimson, claws brown. 
Columba corensis Gmel. 
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; u:ebs 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, 
while others were merely depressions in soft beds of a 
Mesembryanthemum-WkQ 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 Ilermanos 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 
