Dana had to spend night alone guarding some hides on shore.
"The coati (a wild animal of a nature and appearance between that of the fox and the wolf) set up their sharp, quick bark."
He obviously didn't see them, or get an accurate description of them.
coati
n.,
pl. 3tis 5Tupi < cua, a cincture + tim, the nose: so called from appearance of its snout6 any of a genus (Nasua) of small, tree-dwelling, raccoonlike carnivores with a long, flexible snout, found in Mexico and Central and South America
Here's a picture of one:
http://www.animaled.com/coati.htm