DISCOVERIES. 161 
species, in comparison with those of the lund, the 
representations were fewer in this, than in either 
of the preceding volumes. The colouring and 
engravings, however, were considered as supe- 
rior. It contains an account of not less than 
sixty new species of water-birds, to be met with 
along the shores and streams of the United 
States. 
The honour which attaches to these discoveries 
is considerably enhanced when we consider the 
peculiar difficulties attending the study of the 
equatic species. Through rough and tangled 
forest tracts, and over dreary pathless plains the 
land bird must patiently be followed, but the 
water bird as it sweeps the ocean, or scours the 
rocks, resorts to retreats which are almost inac- 
cessible. This Audubon proved, when com- 
pelled to urge his boat onwards, for miles, perhaps, 
beneath a burning sun, tormented the while with 
swarms of insects—to lie’ on the edge of a preci- 
pice some hundred feet above the waters, or to 
crawl along its brink in order to procure a single 
specimen | 
American ornithology is rich in the aquatic 
tribes. Of the heron it contains numerous spe- 
cies. It possesses also the cormorant, the pelican, 
the ibis, the curlew, the tern, the petrel, the gull, 
and others 
Of the cormorants the double-crested is the 
14* L 
