7 12 Anthony, Avifauna of the Revillagigedo Islands. I q"j 



the fourth of the group and is but a high rock having the appear- 

 ance of a ship under jury masts, and lies 65 miles northwest of 

 Socorro. 



The islands are all volcanic in origin and, in general, extremely 

 rough and broken. On San Benedicte is found a heavy growth 

 of coarse grass, wherever there is sufficient soil. But little other 

 vegetation is found on the island. This grass, growing to the 

 height of a man's head, made travel extremely disagreeable, as 

 the barbed seeds penetrated our clothing by thousands and caused 

 us much more trouble than the cactus thickets which we encoun- 

 tered on Clarion later. San Benedicte is a small island about 

 three miles in length with an average width of half a mile. 



Socorro Island was roughly estimated to contain 100 square 

 miles, and to rise to a height of 4000 feet at its center, which is 

 an extinct volcano. The greater part of the island is covered by 

 a very dense growth of underbrush, the weather side (north and 

 northwest exposures) being especially thickly covered, making 

 travel, except in favored spots, well nigh impossible. Trees are 

 abundant on the weather side of the island but on the south and 

 east sides they are mostly confined to the cailons, and were smaller 

 than on the northern slopes. They were nowhere seen over forty 

 or fifty feet in height, though usually covering considerable^ area 

 with their broad spreading branches. Three anchorages were 

 made at Socorro, one on the north side and two on the south 

 coast of the island. 



Clarion Island has little in common with the others of the 

 group, either in flora or fauna. It is only about five miles in 

 greatest length by a mile in width, rising about 1500 feet in alti 

 tude. A few low trees or shrubs, the largest not over ten feet in 

 height, are scattered along the main plateau, and in a few places 

 reach the level ground that lies between the mesa and the coast on 

 the south side. Nearly the entire flat between the mesa and the 

 beach is covered with a dense growth of cactus (^Platofuntia) 

 over which has grown a mass of vines. Passage through this belt 

 is only accomplished with diligent and constant use of the bush 

 knife. 



A short distance from the beach were found two small shallow 

 ponds which contain water during the rainy season only, but as 



