300 CALIFORNIA ACADEMY OF SCIENCES  [Proc. 471 SER. 
appropriate to quote most of their remarks by way of intro- 
duction to the present paper: 
“Cocos Island lies in latitude 5° 33’ north and longitude 87° 
2’ west. It is about four miles long in its longest diameter, 
which is east and west, and has a circumference of about thir- 
teen miles. Its highest part, on its western side, is visible from 
a distance of sixty miles. The island is mountainous, present- 
ing on all sides perpendicular cliffs, and above these steep 
slopes and canyons. The northern side, however, has several 
indentations. * * * Streams of fresh water flow down on all 
sides of the island, in most places pouring over the cliffs into 
Eevaceai 
“The rock composing Cocos Island is volcanic, but is not 
made up of layers of lava as is the case with the Galapagos. 
Rivillagigido and Guadalupe Islands, but, at least about Chat- 
ham Bay, forms one solid mass as does the volcanic rock on 
Clipperton Island. The surface is greatly eroded, there being 
everywhere, as before stated, numerous deep canyons, and the 
rock is almost everywhere covered by a rich shallow soil. 
“The climate resembles that of Clipperton, being extremely 
humid. The island lies in the warm counter equatorial current 
which flows past Cocos in an easterly direction towards Panama 
Bay, where its waters are deflected to the north and south. 
With the currents flowing as they now do, it is apparently im- 
possible for plants or animals to be carried by them from the 
mainland to Cocos Island. 
“The vegetation is extremely rich, though the number of 
plant species is few. Everywhere a dense covering of tall trees 
and smaller undergrowth clothes the irregular mountain slopes 
and ridges. In this respect Cocos strongly contrasts with any 
other island of the eastern tropical Pacific. Guadalupe Island, 
the Rivillagigido and Galapagos archipelagos are for the most 
part dry and barren, even the wettest parts of the Galapagos 
being far less humid and less thickly covered with vegetation 
than is Cocos. 
“Animal life on Cocos Island is very scarce. Besides the 
birds there is present a rat, Mus norwegicus, brought hither by 
vessels that have touched here for wood and water. A lizard, 
Anolis townsend, is rather numerous. With the exception of a 
