242 CALIFORNIA ACADEMY OF SCIENCES  [Proc. 47H Serr. 
- Squatarola helvetica Black-bellied Plover Not common 
Tringoides macularius Spotted Sandpiper Not common 
Dolichonyx oryzivorus Bobolink Not common 
Hirundo erythrogaster Barn Swallow Not common 
Larus franklini Franklin’s Gull A chance visitor 
Stercorarius pomatorhinus Pomarine Jaeger A chance visitor 
Symphemia semipalmata Willet A chance visitor 
Helodromas solitarius Solitary Sandpiper A chance visitor 
Pandion haliaétus Osprey A chance visitor 
Heteropygia bairdi Baird’s Sandpiper Rare; one taken by 
Harris Expedition 
Steganopus tricolor Wilson’s Phalarope Rare; three taken 
Querquedula versicolor Brilliant Teal Rare; one said to have 
been taken by Kinberg 
Mr. Gifford states further: “With the exception of Querque- 
dula versicolor, all of these species occur in the United States. 
Q. versicolor is a straggler from South America. The others 
probably occur each year in about the numbers indicated. The 
Galapagos Islands seem to be out of the general route of migra- 
tory birds, being too far out to sea.” 
, Of the twenty birds of Mr. Gifford’s list, three are com- 
mon, five are fairly common, nine are not common, and three 
are rare. While this list of birds is not large, the number of 
species of plants that are found on the islands is correspond- 
ingly small, and when one considers the fact that almost any 
kind of plant, whether halophytic, xerophytic, or mesophytic, 
which should happen to be introduced, would find a suitable 
habitat on some part of many of the islands, it is not unreason- 
able to suppose that if the islands have been visited pretty con- 
stantly by a small number of birds for a long time, quite a large 
number of plants might have been introduced by them. While 
migratory birds must not be considered as the only factor in 
distribution, they seem in this instance to be the most important 
cause, as the presence of many of the plants found on the 
islands, especially those of a mesophytic character, can be 
explained in no other way. + 
The following table, which has been compiled from various 
sources, shows the number of species, varieties, and forms in 
each family that are endemic, and also those which are common 
to the regions indicated at the heads of the different columns. 
