50 PATAGONIAN EXPEDITIONS : NARRATIVE. 



I was amazed at the extreme abundance of a certain species of amphipod, 

 Hyalella patagonica. These little Crustacea were present in such numbers 

 that, in places over the sides and bottom of the pool, they appeared as 

 animated masses from one to two inches in depth and several inches in 

 diameter. Nowhere else did I see them in such numbers, though they 

 were everywhere the most abundant and omnipresent forms of animal 

 life in the fresh waters of the region. 



Supper over, we spread out our beds and retired for the night without 

 other shelter than that afforded by our tarpaulin, which, however, was 

 ample. It was to both of us a great relief to be able to feel that we were 

 at last in a position to commence the work which we had undertaken and 

 looked forward to with so much anticipation. On the following morning 

 we resumed our journey, intending to cross the Gallegos River at Guer 

 Aike and establish a permanent camp on the north side at some point 

 from which we could conveniently examine the exposures shown in the 

 lofty cliffs, which there formed the left bank of the stream, for vertebrate 

 fossils. On arriving at the crossing, however, we discovered, much to our 

 dismay, that the stream had risen to a height sufficient to render it impas- 

 sable with a cart. We therefore decided to camp temporarily a little dis- 

 tance above the ford and devote our attention to the immediate vicinity, 

 until such time as the water in the river subsided sufficiently to permit 

 of crossing. Selecting a suitable camping place, we pitched our tent, put 

 up our stove, and prepared to make ourselves comfortable for whatever 

 time fortune might necessitate our remaining at this locality. After par- 

 taking of a hastily prepared lunch, I saddled my horse and rode away up 

 the river to examine some exposures which were distinguishable a few 

 miles distant, while Mr. Peterson occupied himself in setting a number 

 of traps for small rodents and in procuring and skinning representatives 

 of the bird life of the vicinity. The exposures mentioned proved to con- 

 sist of rather fine-grained, light-colored sandstones, composed largely of 

 volcanic ash, exhibiting frequent examples of cross-bedding, though 

 remarkably destitute of vertebrate or other fossils. I returned to camp 

 late in the evening, not forgetting however to stop and break down a 

 bunch of dead calafate bushes, Berberis cuneata, which I had 'detected 

 shortly after leaving camp. These, when dragged into camp with 

 my saddle rope attached to the horn of the saddle, furnished fuel 

 sufficient to enable us to pass a comfortable evening in the tent about a 



