THE VOLCANO IRAZU 133 



Altitude 

 Designation Diameter Altitude of Rim of Bottom 



J 3170 3150 



L 3 1 60 < 3 1 60 



("knife edge") 3330 



C and L are still smaller craters not shown on our sketch-plan. 



All dimensions are given in meters. 



The course which we followed Is shown by the dotted line 

 on the sketch-plan. From time to time the mist blew in so 

 heavily as to blot out everything from view. At such times 

 we sat down in the lee of a bush, covered ourselves and es- 

 pecially the cameras with the poncho and waited, some- 

 times half an hour, until the mist cleared away and then 

 resumed our walk. In spite of these drawbacks we were 

 able to get some photographs while making this circuit. 

 All of the craters, mother, daughters and granddaughters, 

 have more or less vegetation on their walls, floors or both. 

 A plant looking like marsh grass, growing in tufts, is char- 

 acteristic of the crater floors and the dead yellowish stems 

 gave a sulphurous appearance to them when seen from a 

 distance; some of this grass too has a decidedly salty odor, 

 which Increases the superficial resemblance to a salt marsh. 



Several species of birds were not uncommon In the craters 

 — a thrush not unlike a robin, some small sweet songsters 

 and humming-birds. Little gray spiders {Pardosa sp.) ran 

 over the ground, a handsome red and yellow bumble bee, 

 apparently of the same species (Bombus ephippiatus) as 

 occurs also around Tierra Blanca, occasionally flew by, 

 small gray moths and flesh flies were abundant. We stopped 

 to photograph a group of beautiful Bromellads growing 

 on the ground beneath the branches of small trees and now 

 in flower; the inflorescence was red and green, the leaves 

 were streaked and spotted with red. On pulling one of these 

 apart we found, in the water between the leaf-bases, live 

 mosquito larvae {Aedes near Ae. aureostriatus) and other 



