238 The Naturalist in La Plata. 
ing this family lkeness in colour, any person, not 
an ornithologist, looking at a collection of speci- 
mens comprising many genera, would hear with 
surprise and almost incredulity that they all belonged 
to one family, so great is the diversity exhibited in 
their structure. In size they vary from species 
smaller than the golden-crested wren to others 
larger than the woodcock; but the differences in 
size are as nothing compared with those shown in 
the form of the beak. Between the minute, straight, 
conical, tit-like beaks of the Laptasthenura—a tit 
in appearance and habits—and the extravagantiy 
long, sword-shaped bill of Nasica, or the excessively 
attenuated, sickle-shaped organ in Xiphorynchus, 
the divergence is amazing, compared with what is 
found in other families; while between these two 
extremes there is a heterogeneous assemblage of 
birds with beaks like creepers, nuthatches, finches, 
tyrant-birds, woodpeckers, crows, and even curlews 
and ibises. In legs, feet and tails, there are corre- 
sponding differences. There are tails of all lengths 
and all forms; soft and stiff, square, acuminated, 
broad and fan-like, narrow and spine-like, and 
many as in the woodpeckers, and used as in that 
bird to support the body in climbing. An extremely 
curious modification is found in Sittosoma: the tail- 
feathers in this genus are long and graduated, and 
the shafts, projecting beyond the webs at the ends, 
curve downwards and form stiff hooks. Concern- 
ing the habits of these birds, it has only been 
reported that they climb on the trunks of trees: 
probably they are able to run vertically up or down 
with equal facility, and even to suspend themselves 
