Geol.— Vol. I.] SMITH— SANTA CATALINA ISLAND. 7 



one degree toward the northern shore. (See figs. 2 and 

 3.) In fig. 2, Black Jack and Orizaba and a portion of 

 the ridge between Silver and Middle Ranch Canons are 

 seen above the main ridge. At the " west end " (that por- 



South. 



North. 



Figure 2 — Outline of the summit of the main ridge west of Avalon Canon, 

 as seen from the summit of the ridge on the opposite side of the canon. 



tion of the island west of the isthmus), the more northerly of 

 the two branches of the main ridge has an average height 

 throughout its length, about 200 feet lower than the other. 

 Thus it appears that in transverse section the island shows 

 a general slope toward the mainland. 



East. 



West. 



Figure 3 — Outline of the summit of the main ridge south of Avalon Caiion, 

 as seen from the summit of the ridge on the opposite side of the canon. 



Two Types of Drainage. — The principal stream canons 

 running from the main watershed are of two types, which 

 may be readily distinguished on the map. Those canons 

 which have their mouths on the northern or landward coast 



